Monday, April 29, 2013

How to prepare for a Surgery?

In the former article about Surgery  we learnt about the basics of it.In the following article , we shall discuss about the preoperative preparation of a patient, from the patient's perspective, and also the technicalities of it. We will look into aspects of operative mortality, determining the risk of an operation and also learn about total parentral nutrition.
The patient's perspective
  • The patient at a preoperative stage is usually in poor physical condition and sometimes also in not a very good psychological condition.
  • The diagnosis itself is wrecking and the physical condition may seem to only worsen after that.
  • The surgeon usually briefs the patient about the surgery that is to be performed.It is only natural for a patient to be anxious from that moment on. But it is extremely important for a good patient to trust the surgeon completely. It is important for the patient to know that his/her life is in extremely skillful hands.This gives them a sense of security and confidence.And this confidence can be gained only if there is good communication between the patient and doctor. Preoperative counselling is sometimes extremely necessary. This can be done by a skilled Psycho-oncologist as well as the Surgeon himself.
Surgery Patient : Doctor with senior patient
doctor communicating with patient
What is the need of preoperative preparation?
  • Tumors have a variety of ill-effects on a patient's health.Some of the effects are often toxic in a manner that is disproportionate to the size and type of tumor.
  • As a result of this, many patients suffer from poor nutritional status.This happens because, in cancers of mouth, pancreas, oesophagus, pharynx, etc, there is interference with normal alimentary function.
  • Unexplained weight loss is known to be a symptom of cancer too.
  • Morover, if pain is one of the horrible symptoms, this may lead to anorexia too.
  • All these factors will make it difficult for the patient to cope up with the surgery.
  • Hence, it is extremely vital that all or most of the nutritional deficits must be corrected before the surgery, because surgical mortality and morbidity rates are high in patients whose physiologic and biochemical deficiencies are not corrected first.
  • Also, hypoproteinemia should be corrected and the blood volume should be restored.
  • Total parentral nutrition is an efficient way of preparing a malnourished patient for surgery.
Total Parenteral Nutrition

What is total parentral nutrition or TPN ?
  • Total parentral nutrition is a method of providing ideal nutrition to patients who are undernourished.
  • Here, a needle or catheter will drip TPN as per Doctor's advise.
  • The TPN solution containing carbohydrates, lipids, proteins, minerals, trace elements, electrolytes etc, will be given as per the need.
  • This will help restore the positive nitrogen balance before a major surgery:

How can one determine the risk in a given operation ?
This is based on a number of factors such as
  • the physical condition of the patient, 
  • other comorbidities
  • cardiopulmonary reserve (function of heart)
  • hepatic (liver) function
  • renal (kidney) function
  • the intent of this specific surgical procedure (curative versus palliative)
  • the technical complexity of  the surgery
  • type of anesthetic used, 
  • the relative experience of the health-care personnel involved
  • For more information, refer to 'the five level physical status classification of the American Society of Anesthesiologists' and the 'Eastern Cooperative Oncology Group five-step performance scale'


What is operative mortality ? 
  • Operative mortality is defined as mortality that occurs within 30 days of an operative procedure.
There are 2 major factors that determine operative mortality:
  • The underlying disease of cancer itself is a major cause of mortality.
  • Old aged or geriatric population is more prone to surgical morbidity and mortality.
However, this factor cannot be used to disqualify them form a surgery which gives good odds of cure.
In case of operations for palliative purposes, it is better to avoid the risk by avoiding high-risk surgeries.
For example, If a patient has intestinal obstruction due to carcinomatosis, the surgery to relieve this will put the patient at 20-30% risk of mortality. In such situations, the risk:benefit ratio must be accurately calculated by the surgeon.

Also read
 5 reasons why you should study Oncology.
Cancer and surgery.
What is Radiation oncology?
What is Cancer-related fatigue?
What is psycho-oncology?
12 causes of cancer.
Cancer in 21st century.

Saturday, April 27, 2013

What is TNM staging?

In the previous article, we discussed about the procedure of  biopsy.This is followed by examination of the sample, and coming to a conclusion about the stage of cancer.This article talks about a very important aspect of Oncology, which is 'tumor staging'. It explains what tumor staging is, why is it essential, and how it's done.

What is 'tumor staging' ?
In simple words, tumor staging is system which shows the extent of malignancy in an individual.
In other words, it describes the stage of cancer.

What is the need for tumor staging?
  • Tumor staging describes various aspects of the primary tumor, like, the anatomic involvement of structures, the size of tumor, the grade of tumor,spread to other regional sites like lymph nodes, and secondary tumor growth or metastasis.
  • All the above mentioned aspects have to be known accurately in order to formulate a treatment protocol, and also establish a prognosis for an individual.
  • On a wider scale, a standard tumor staging system is absolutely essential to be able to compare results of different treatments in different centers.
  • Also, newer therapies can be evaluated by comparing them with the present therapies for the same stage of cancer.

Tumor Staging : Laryngeal cancer
stages of laryngeal cancer
What are the various tumor staging systems?
  • The American Joint Committee on Cancer (AJCC) had recommended a staging system ranging from stage I (small, localized carcinoma ) to stage IV (distant metastatic spread). However, this is not widely used.
  • The widely used system is called TNM staging system, as it gives more information about the tumor.

TNM staging:
  • T stands for the primary tumor 
  • N stands for the presence or absence of involvement of lymph nodes
  • M stands for the presence or absence of distant metastases .
  • After the T, increasing numerals like T1, T2, T3, or T4, indicate lesions of larger size that usually indicate a poor prognosis. 
  • N0 indicates no spread to lymph nodes.
  • N1 indicates spread to the lymph nodes. For more extensive nodal involvement, additional numbers can be used. 
  • M0 indicates absence of metastasis
  • M1 indicates presence of  distant metastasis. 
For example, There is a small lesion that has neither spread to regional nodes nor metastasized to distant sites.It would be designated as T1 N0 M0.
If there is a large lesion that involves the regional lymph nodes but not distant
sites may be identified as T2 N1 M0.
If there is a large neoplasm associated with both regional lymph nodes and distant metastases would be designated as  T3 N1 M1.

NOTE: For some tumors, a G for grade of malignancy is added.
Eg, soft tissue sarcoma.
High-grade tumors are less-differentiated and tend to metastasize sooner.


Classifications of the TNM system:
The TNM system is classified chronologically, or according to the time period when it is used.
  • cTNM or TNM is also referred to as 'clinical classification'
This stands for the extent of cancer before the treatment began.
It is determined by results from physical examination, imaging studies, biopsy, endoscopy,exploratory surgery, etc.
  • pTNM is the 'pathologic classification' 
It includes the information obtained during the pathological examination of tumor, or even during surgery.
  • rTNM stands for 're-treatment classification'
It is used for staging the recurred cancer or relapse after a disease-free period of remission.
It includes some evidence of recurrence which maybe clinical or pathological.
  • aTNM stands for 'autopsy classification"
This is based on a postmortem examination.


Also read
5 reasons why you should study Oncology.
Cancer and surgery.
What is Radiation oncology?
What is Cancer-related fatigue?
What is psycho-oncology?
12 causes of cancer.
Cancer in 21st century.



What is Excisional Biopsy?

What is Excisional Biopsy?
Excisional Biopsy is used to completely remove the tumor mass.


What are the indications?/when is it performed?
  • When tumor masses are small and discrete, about 2-3 cm in diameter.
  • When complete removal with wide excision is possible without any interference.
  • Performed when the entire lesion has to be examined.
  • When a definitive diagnosis cannot be made from tissue removed by incisional biopsy.
  • Eg, superficial squamous or basal cell carcinomas or malignant melanomas.
  • Also used for polypoid lesions of the colon, for thyroid and breast nodules, for small skin lesions.

What are the contraindications?/ When is it not performed?
  • It is contraindicated in large tumor masses because there are chances of spilling of tumor cells throughout a wide surgical field, which can be corrected only by total surgical resection of that part.
  • Eg, skeletal and soft tissue sarcomas.

Biopsy: excisional
Excisional Biopsy

Facts :
  • The excisional biopsy margins are always marked with sutures or metal clips so that if further excision is needed, the margin of previous excision can be properly located.
  • Orientation of biopsy incisions is also extremely important, otherwise additional tissue planes will be opened up unnecessarily.This will lead to wider radiotherapy fields or more extensive ultimate surgical resections.
  • Biopsy of tumors in extremities or limbs is done using incisions that run parallel to the long axis of that limb. This will lead to a definitive total or en bloc resection that also includes the biopsy track.
  • Biopsy incisions are closed carefully because a hematoma can lead to spilling of tumor cells and contamination of tissue planes.

Biopsy and Lymph Nodes
  • Lymph nodes should always be carefully selected for biopsy.
  • Enlargement of the upper cervical nodes points at metastases or secondary spread usually caused by laryngeal,oropharyngeal, and nasopharyngeal primary tumors.
  • On the contarary, supraclavicular nodes are usualy enlarged due to metastases from  the thoracic or abdominal cavities or breast, which is the primary site.
  • Axillary nodes are chosen for biopsy over groin nodes if both are enlarged as this decreases likelihood of postoperative infection.
  • Cervical lymph nodes are not biopsied until a primary tumor has been searched using nasopharyngoscopy, esophagoscopy, and bronchoscopy.
  • After the biopsy, a specimen is usually sent for pathological exam by preparing a frozen section or a permanent section.
  • Frozen sections are made at the time of biopsy itself, and the result can be obtained within 10-20 minutes.

Lymph nodes: biopsy
lymph nodes Biopsy


Procedures like mediastinoscopy, laparoscopy (peritoneoscopy), thoracoscopy, exploratory thoracotomy, or even laparotomy are performed to obtain  'representative tissue' samples for microscopic examination to confirm diagnosis or tumor stage.

Also read
5 reasons why you should study Oncology.
Cancer and surgery.
What is Radiation oncology?
What is Cancer-related fatigue?
What is psycho-oncology?
12 causes of cancer.
Cancer in 21st century.

What is Incisional Biopsy?

Incisional Biopsy
In the previous article about biopsy, we saw the basics of it, learnt some facts, and discussed needle biopsy. In this article , we will discuss about 'incisional' and 'excisional' biopsies, their indications and contraindications, etc.

What is Incisional Biopsy?
  • Incisional biopsy is a procedure used for pathologic examination of a tumor.
  • It involves removal of a small portion of the tumor mass.
  • If possible, an incisional biopsy should retrieve a deep section of tumor as well as a margin of normal tissue for examination.


Biopsy: incisional
Incisional biopsy
What are the indications for performing incisional biopsy/when is it performed?
  • It is best performed in situations where the surgeon will be able to excise or remove the 'incisional wound' in continuity, in case the tumor cells spilled out at the time of biopsy.
  • It  is indicated for deeper subcutaneous or intramuscular tumor masses after the initial needle biopsy fails to establish a diagnosis.
Performed in case of very large tumors, as the total excision would damage extensive healthy tissue planes.

Facts:
Incisional biopsy includes the following :
  • removal of tumor portions during endoscopic examination of the bronchus, esophagus, rectum, or bladder, 
  • also includes suction or currettage of the endometrium as well as laparoscopic biopsy.

Disadvantage of incisional biopsy:
  • It's the same as that of needle biopsy.Removed portion may not be representative of the entire tumor.
  • Negative results after incisional biopsy does not rule out the possibility of cancer in the residual mass, especiallly if the clinical features suggest otherwise.



What is Needle Biopsy?

Needle Biopsy 
Here, 2 types of needle biopsies are discussed, 
  • Fine-needle aspiration (FNA) or Fine- Needle Aspiration Cytology (FNAC)  is a technique in which the cells are aspirated from a tumor using a needle and syringe using  'negative pressure'.
  • This technique can also be performed using image-directed guidance.
  • It is helpful for diagnosing  deep visceral tumors, which are relatively inaccessible.
  • The aspirated tissue does not contain an  intact tissue.
  • Because of this, FNA cannot distinguish invasive from noninvasive malignancy.
  • For this purpose, other types of biopsy may be more appropriate, if one has to differentiate carcinoma in situ from an infiltrating tumor.
needle biopsy of breast
Needle biopsy of Breast


  • Cutting core biopsy is a method of pathologic diagnosis, whereas FNA was cytologic. 
  • This is  useful for biopsy of subcutaneous masses (below the skin), muscular masses (in the muscles), as well as some internal organs, such as liver, kidney, and pancreas.
  • This method is relatively inexpensive and causes minimal disturbance of the surrounding tissue.
  • It is  performed with a large-bore needle, such as the Vim Silverman or Tru Cut type. 
  • This technique is used to obtain a small piece of intact tumor tissue.
  • This allows the pathologist to study the invasion of  cancer cells in the surrounding microenvironment.
  • The risk of implanting tumor cells in healthy tissue during biopsy is extremely small.
  • Needle biopsy should not be used if the specimen is small, because this increases the chances of the needle missing the lesion.
  • Whereas, the biopsy may not even represent of the entire tumor.
Lastly, if the result of tissue obtained by needle biopsy is not consistent with the clinical presentation of the lesion, then incisional or excisional biopsy should be performed.
Also read
5 reasons why you should study Oncology.
Cancer and surgery.
What is Radiation oncology?
What is Cancer-related fatigue?
What is psycho-oncology?
12 causes of cancer.
Cancer in 21st century.

What is Biopsy ?

BIOPSY FOR DIAGNOSIS OF TUMORS
'Biopsy' is a common term used when it comes to diagnosis to cancer. Let's look into some facts about this surgical procedure and understand various aspects of it.

What is Biopsy?
  • Biopsy is a minor surgical procedure, where a small cell mass or tissue mass is extracted from a suspicious looking site.
Why is Biopsy needed?
  • For diagnosing a tumor mass, it is essential to first locate the tumor mass and then perform a biopsy.
  • The evidence then obtained in biopsy, is will be used to determine the histology (type) and grade of the tumor.
  • Then on, a treatment protocol can be formulated.
Facts about Biopsy:
  • The pathological interpretation of the mass obtained in a biopsy is relevant only if the 'representative section' of the tumor is extracted.
  • Biopsy is easiest if the tumor is near the surface of the skin.
  • Biopsy can be done easily if the tumor involves an orifice or a natural opening of the body like mouth, anus, etc. This makes it possible to have image-directed needle biopsy using bronchoscope, colonoscope, cystoscope, etc.
  • In cancers of breast, rectum , tongue, etc, the tumors can be usually seen, or easily palpated, and an efficient biopsy can be obtained.
  • Whereas, the deep seated tumors can grow very large and yet remain without any symptoms. Here, techniques like UltraSonography (USG), Commuted Tomography (CT scan) and Magnetic Resonance Imaging (MRI) have to be used to locate the tumor for biopsy.
  • In some patients, an exploratory surgery is required to obtain a definitive biopsy.
  • Nowadays, the procedure of Biopsy is minimally invasive, and is performed at an 'out-patient' basis where the patient does not have to be admitted in the hospital.
What are the types of Biopsy?
Three methods of Biopsy include




Friday, April 26, 2013

What is Surgical Oncology ?

Cancer and Surgery
Surgery, as some like to say, is a controlled trauma caused by a surgeon, in order to add years to life.
Surgery plays a very important role when in comes to cancer, in terms of diagnosis, cure, reconstruction and even salvage. Lets look into various aspects of surgery in cancer.

Surgery :
  • oldest modality for treating cancer 
  • widely used to treat solid tumors
  • more patients are cured by surgery when used as a single treatment, as compared to any other type of cancer therapy. 
''Even in the contemporary cancer curing
multi-modality milieu, it is rare to find a patient with solid
tumor whose care does not include a surgical component''
cancer surgery
Cancer Surgery
Principles of Surgery in Oncology:
  • Zero-order kinetics - Surgery in oncology operates by Zero-order kinetics, where 100% tumor cells present in the operated area are killed or removed at once.
  • Chemotherapy and Radiotherapy operate by First-order kinetics, where a fraction of tumor cells is killed at once.
  • Surgery primarily reduces the 'tumor burden' and this helps the adjuvant therapies to kill the residual tumor cells.
For instance,  if there is a localized primary tumor, an en bloc surgical procedure can be performed to get rid of the gross and microscopic tumor in all the related and adjacent anatomic locations.
Surgery is the most effective treatment of localized primary
tumor disease and associated regional lymphatics.

Onco-Surgeon :

  • The cancer surgeon  functions as a member of theoncology team, which includes a clinical oncologist, radiation oncologist, a nurse, care-giver, etc.
  • The cancer surgeon is frequently the first oncology specialist that a patient will usually consult.


Role of a Surgeon :
  • establish a diagnosis of a suspicious lesion
  • make a surgical decision whether to operate or take other biopsy 
  • secure the diagnostic-quality tumor tissue
  • communicating the findings to the patient
  • complete the procedures needed to stage the patient 
  • initiate the interaction between patient and other members of the multi-modality oncology team
  • initially explain to the patient the sequence and rationale of the various treatment components that will be used to manage their specific malignancy
  • provides initial information about prognosis and make decisions about follow-up care and surveillance to detect tumor recurrence
  • Present in the short as well as the long-term components of the disease process of a patient
  • The cancer surgeon also holds the knowledge of different therapeutic options available, the natural course of the given malignancy, and how these factors will be integrated into sequencing the various treatment modalities, best suited for the patient.
In the succeeding article, know more about Biopsy .

Also read
5 reasons why you should study Oncology.
What is Radiation oncology?
What is Cancer-related fatigue?
What is psycho-oncology?
12 causes of cancer.
Cancer in 21st century.

Friday, April 12, 2013

12 causes of Cancer | Irradiation

12 causes of Cancer : Irradiation
Radiation is everywhere, be it from the sun, or from the electronic devices at our homes. But not all are harmful, and not all cause cancer. There are basically two types of radiations- ionizing and non ionizing. The ionizing radiation is the high frequency radiation which can potentially damage the DNA of the cells causing mutation. The Ionizing radiation is a known Carcinogen or cancer causing agent. The ionizing radiation includes the X rays , Atomic radiation, and high energy UV rays.

X rays-
Constant exposure to X rays causes certain cancers. This was a new finding when the X ray machine was still in its developing stage. The workers or technicians who manually held the X ray plates, developed certain Cancers , mostly affecting the skin of their hands.
X Rays Exposure : close up of human leg bone X-rays
avoid unnecessary X rays

Atomic Irradiation-
After the bombings at Hiroshima and Nagasaki in Japan, there was high incidence of Leukemia and thyroid cancer in the surviving population.
Also, the same was found after the accident in Chernobyl in 1986.
Atomic Irradiation  : Radiation sign on map of Japan
atomic irradiation in Japan

UV rays-
We discussed the role of UV rays in the previous article about Sunlight exposure.

Types of Cancers caused by ionizing radiation are-
  • thyroid cancer
  • leukemia
  • multiple myeloma
  • skin cancer
  • breast cancer
  • stomach cancer


Refer to the main article 12 causes of Cancer to see how Cancer develops.

Also read
5 reasons why you should study Oncology.
Cancer and surgery.
What is Radiation oncology?
What is Cancer-related fatigue?
What is psycho-oncology?
12 causes of cancer.
Cancer in 21st century.

Wednesday, April 10, 2013

12 causes of Cancer | Sunlight exposure

12 cause of Cancer : Sunlight exposure.
Tanning Bed : husband and wife relaxing on sunbeds on the beach and smiling at camera. Horizontal shape, rear view, copy space

  • The Ultra Violet or UV rays are responsible for most of the cases of Melanoma or skin cancer, especially in the western countries.
  • Every person living on earth is more or less always exposed to sunlight. So why are only the people in the west mostly found to have skin cancers?
  • There are 2 main reasons for this :



Tanning Bed : Handsome young man relaxing during a tanning session in a modern solarium
  • The effect of sunlight exposure on the people is such that, it doesn't lead to more melanin production (like in dark skinned people), but it slowly alters the genetic constitution of the cells, and leads to mutations. A series of which results into skin cancer. 
  • Increasing use of 'Tanning bed' which mainly emit UVA rays, which are responsible for causing Melanoma.
Skin Cancer : Woman aplicatin sun lotion on her shoulder with sun rays Stock Photo
So, these are the 2 main causes of skin cancer which are again, preventable. And can be prevented by simple protective measures like covering the skin and use of a good sunscreen. Also, avoiding the use of 'Tanning beds' reduces the risk.

Saturday, April 6, 2013

12 causes of Cancer | Betel nut

12 causes of cancer : Betel nut-
Betel nut chewing is a very common cause of oral cancer in the South-East Asian countries, where it is locally produced and highly consumed.
Betel Nut : rows of betel nuts with betel leaf
betel nut
An interesting fact about betel  nut chewing is that, it's more of a cultivated habit, than being chewed because it is addictive.

In the rural areas, a mixture of betel nut, tobacco leaf and lime is widely used, which is highly carcinogenic.
This mixture is usually held in the cheek area inside the mouth. This stays in constant contact with the lining or buccal mucosa and is responsible for cancer.
Betel Nut Tobacco Lime : Betel leaf with a vintage pot of lime
mixture of betel nut, lime and tobacco
People start consuming the mixture even in  childhood, as early as 10 years of age.
This is one of the major causes of oral cancer in India.

To know HOW cancer is caused, see the main article 12 causes of Cancer

Also read
5 reasons why you should study Oncology.
Cancer and surgery.
What is Radiation oncology?
What is Cancer-related fatigue?
What is psycho-oncology?
12 causes of cancer.
Cancer in 21st century.

Wednesday, April 3, 2013

12 causes of Cancer | Alcohol

12 causes of Cancer : Alcohol

Firstly, alcohol consumption is directly associated with liver cancer in a way, that it causes liver cirrhosis which may turn into liver cancer later on.
Alcohol Cancer : liver cancer
liver cancer
Secondly, alcohol, if consumed along with tobacco smoking, HIGHLY increases the chances of developing:
  • alimentary canal cancer
  • pancreatic cancer
  • cancer of colon, etc

Alcohol Cancer : Man drinking from a bottle and holding a cigarette between his fingers
smoking and drinking
These chances are lower in people who consume either alcohol or tobacco alone.
Esophageal cancer is associated with alcoholics who usually consume strong spirits.

Alcohol consumption is another risk factor which can be totally prevented.

To understand HOW cancer is caused, or to understand the basic pathway, see the main article
12 causes of cancer.

Also read
5 reasons why you should study Oncology.
Cancer and surgery.
What is Radiation oncology?
What is Cancer-related fatigue?
What is psycho-oncology?
12 causes of cancer.
Cancer in 21st century.

Tuesday, April 2, 2013

12 causes of Cancer | Smoking or tobacco chewing

12 causes of Cancer :smoking and tobacco chewing

Cigarette smoking:
  • Smoking is the leading cause of not only cancer , but a myriad of other modern health problems too.
  • It is obviously the highest preventable and controllable risk factor. 

Mouth Cancer : Closeup on ashtray with cigarette butts and a pipe Stock Photo
cigarette and pipe smoking

Smoking may cause the following cancers :

  • Lung cancer
  • Oral cancer
  • Cancer of larynx and throat
  • Esophageal cancer
  • Stomach cancer
  • Pancreatic cancer
  • Breast cancer
  • Kidney cancer
  • Bladder cancer
  • Cancer of cervix and uterus


Tobacco Chewing:
  • This causes the very dreadful and disfiguring oral cancer besides many other oral cavity problems.
  • Again, this factor is highly controllable and preventable.
oral cancer
To understand HOW smoking and other facors cause Cancer, or to understand the basic pathway, see the main article 12 causes of Cancer.
For more information and latest statistics visit oral cancer causes / wikipedia

Also read
5 reasons why you should study Oncology.
Cancer and surgery.
What is Radiation oncology?
What is Cancer-related fatigue?
What is psycho-oncology?
12 causes of cancer.
Cancer in 21st century.

Monday, April 1, 2013

12 causes of Cancer.

How is Cancer caused?

We know that a complex disease like Cancer does not have 'one common cause' which is very simple, preventable, and easy to understand. For decades now,  researchers have been studying its cause , with a huge sum of money invested, using the best existing technology there is. And this has equipped us with the understanding of a  basic pathway that leads to Cancer. Let's have a look...
Cancer : Cancer cells spreading and growing as malignant cells in a human body caused by environmental carcinogens and genetic causes as tumors and cell damage are treated to cure the disease.
cancer cells spreading
Understanding basic pathway of cause of Cancer :
First of all, a single pathway for cause of cancer does not exist presently, and if it does, it's not yet found. But there are a few common sequential things that go wrong in and around a cell, which ultimately leads to cancer. So, lets take a look at those common factors.

  • The one basic factor is, damage to the DNA or genetic blueprint of the cells, which causes mutation or sudden change.
  • This change happens in the 2 genes that regulate the cell's multiplication as we discussed earlier, the proto-onco genes and the tumor suppressor genes.
  • Now, not all types of damage to the DNA  will produce the same effect in these genes. That's how we get a variety of cancer types
  • The specific thing that damages the DNA of a cell, often determines the type of Cancer. 
  • For example, the damage caused to the cell because of carcinogen in tobacco and UV rays of the sun is very different. Each 'cause' or way of damage to a cell has a signature effect on the mutation of the cell, and hence produces a particular type of Cancer. The same applies to a virus that causes cancer as well.
  • Now, is one mutation in one cell enough for producing cancer? No. It takes a series of mutations in that cell for it to undergo a cancerous change.
  • This is the reason why Cancer does not happen after a year of smoking. It requires constant and long-term exposure to a carcinogen before cancer shows up. It waits for the body to become vulnerable and incapable of repairing the damage before it shows up!
  • In case of familial cancers, they show up earlier than usual. The reason is that, the mutated genes are already present in that particular individual, inherited from the parents. So a little bit of exposure to the carcinogens is all it takes.


Apoptosis gone wrong :
Apoptosis is the self-regulation of cell growth, or a mechanism of natural cell death. Usually, when the cells are physically worn out, or genetically damaged, the undergo apoptosis, so that they are replaced by new normal healthy cells and the function of cells is not compromised. But when this process goes wrong, the genetically damaged cells continue to proliferate and become malignant.

Now that we have a basic understanding of what goes wrong, let's have a look at some common reasons WHY it does : 12 causes of cancer

1. Smoking or Tobacco chewing
2. Alcohol consumption
3. Betel nut
4. Sunlight exposure
5. Irradiation or radiation exposure
6. Irritants
7. Chemical Carcinogens
8. Hormonal imbalance
9. Viruses
10.Bacteria
11.Pre-existing genetic abnormalities
12.Faulty food habits

The 12 common causes of cancer will be discussed in detail in the further articles.

Also read
5 reasons why you should study Oncology.
Cancer and surgery.
What is Radiation oncology?
What is Cancer-related fatigue?
What is psycho-oncology?
12 causes of cancer.
Cancer in 21st century.