CANCER – A DISEASE  THAT FRIGHTENS AND TOUCHES MANY OF US

After cancer is diagnosed, the doctor will want to learn the extent of disease. Staging is a careful attempt to find out whether the cancer has spread and, if so, to which parts of the body.  Treatment decisions depend on the results of staging.  

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Healthcare In Udupi

Introduction:
Cancers in all forms cause 12% of deaths throughout the world. Cancer can be defined as a group of many related diseases that develop over a multi step process, it begins in cells, the body’s basic unit of life. Cells in cancer are abnormal and divide without control or order.  They can invade and damage nearby tissues and organs.  Cells in cancer can break and enter the blood stream or the lymphatic system.  This spread of cancer is called metastasis. Leukemia and lymphoma are cancers that arise in blood forming cells. The abnormal cells circulate in the blood stream and lymphatic system.  Most cancers are named from the organ or type of cell in which they begin.  For example, cancer that begins in the lung is lung cancer, and cancer that begins in cells in skin known as melanocytes is called melanoma. In India, cancers rank third as a cause of death and possibly accounts for 9.5% of all deaths.  WHO estimates by the year 2000 the number of cancer deaths will be around 8 million annually worldwide.  It is estimated in India at a given time, there are approximately 25 lakh cases of cancer.  Eight lakh new cases are being detected each year.  Nearly 50% of these cases die. The age adjusted incidence rate for both sexes is 100-140 cases per 100,000 population for all types of cancers in urban India.

Table I

MOST FREQUENT CANCERS IN INDIA

Male

Female

Mouth/Oropharynx

Cervix

Esophagus

Breast

Stomach

Mouth/Nasopharynx

Lung

Esophagus

Prostate

Ovary

Colorectal

Colorectal

Liver

Liver

As per estimates in 1996, there are 18 million persons with cancer surviving up to five years after diagnosis. These numbers over the years are increasing due to availability of treatment modalities in more places and development of innovative newer methods of treatment.

Before the discussion of newer treatment methods available for cancer, a brief note on the possible causes, prevention, symptoms, diagnosis, staging and how is handle a diagnosis in appropriate.

Possible causes and prevention of cancer:
We are learning more about the causes of cancer and finding out ways to prevent it.  Scientists and researchers in both laboratory and population are exploring possible causes of cancer, and are also identifying the risk and protective factors.  Even though we as doctors can seldom explain why one person gets cancer and another does not, it is clear that cancer is not caused by injury and it is not contagious.  Cancer develops overtime.  It results due to a complex mix of factors related to lifestyle, hereditary, and environment.  Some people are more sensitive than others to these factors and hence get cancer.

Table II

RISK FACTORS ASSOCIATED WITH CANCER

Tobacco

Diet

Ultraviolet radiation

Alcohol

Ionizing radiation

Chemicals and other substances

Hormone replacement therapy (HRT)

Close relatives with certain type of cancer

DES diethylstilbestrol

People who have any of the cancer risk factors listed above should talk with their doctor.  The doctor may be able to suggest ways to reduce the risk and can recommend an appropriate schedule of check ups.

Symptoms of cancer

Cancer can cause a variety of symptoms.  These are some of them.

Thickening or lump in the breast or any other part of the body

A sore that does not heal

Obvious change in  wart or mole

Changes in bowel or bladder habits

Nagging cough or hoarseness

Unexplained changes in weight.

Indigestion or difficulty swallowing

Unusual bleeding or discharge

When symptoms occur, they are not always caused by cancer.  It is important to see the doctor about any of these symptoms or about other physical changes. Only a doctor can make a diagnosis.  One should not wait to feel pain.  Early cancer usually does not cause pain.

Diagnosis

If symptoms are present, the doctor asks about the person’s medical history and performs a physical exam, in addition to checking general signs of health, the doctor may order various tests and exams. These may include laboratory tests and imaging procedures.  A biopsy is normally necessary to determine whether cancer is present.  Special tests to measure the amount of certain substances called tumours markers in the blood, urine and certain tissues are done in all cancer centers..  Images (pictures) of areas inside the body help the doctor see whether a tumor is present, Several ways of taking pictures (imaging) include conventional x-rays, ultra sonograms, CAT scan, MRI scan and radio nuclide scanning.

A biopsy is almost always necessary to help the doctor make a diagnosis of cancer.  In a biopsy, tissue is removed for examination under a microscope by a pathologist.  Presently apart from conventional microscopic examination, pathologists often use newer methods to sub classify cancer for more refined treatments.  This is done by methods such as Immunohistochemistry, cytogenetics, electron microscopy and molecular oncology studies.

Staging

After cancer is diagnosed, the doctor will want to learn the extent of disease. Staging is a careful attempt to find out whether the cancer has spread and, if so, to which parts of the body.  Treatment decisions depend on the results of staging.  The doctor may order more laboratory tests and imaging studies and additional biopsies to find out whether the cancer has spread.

Handling the diagnosis

Anyone facing cancer are concerned about what the future folds for them. Patients need to understand the nature of cancer and what to expect, this can keep patients and closed relatives to plan treatment, anticipate life style changes and make financial decisions.  Doctors are often faced with problems of discussing a patient prognosis.  Prognosis is a prediction of the future course and outcome of a disease and an indication of the likelihood of recovery from the disease“cancer”, however, this is only a prediction and doctors are only attempting to project what is likely to occur for that individual patient, certainly always prognosis of cancer depends on response to a particular treatment. In addition a host of other factors like type of cancer, stage of disease and its grade, patients age and general health, etc., also determine outcome to treatment.

Statistics are often used to figure out individual chances of being cured from cancer.  Statistics are seldom helpful for individual patients and their families. These reflect the experience of large groups of patients done at major cancer centers worldwide.  These off course cannot predict what will happen to a particular patient, but gives a rough estimate for the patient, his chance of cure or recovery.

Seeking information about prognosis and statistics can help some people reduce their fears.

Treatment

Treatment for cancer depends on the type of cancer, the size, location and the stage of the disease, the person’s general health and other factors.  The doctor develops a treatment plan to fit each person’s situation.

Cancer treatment requires often a team of specialists, which may include a Surgical Oncologist, Radiation Oncologist, Medical Oncologist and others.  The major forms of treatment available for treatment of cancer are surgery, radiation therapy, chemotherapy, hormone therapy or biological therapy.  Many times a combination these treatments are necessary. Application of combined treatments of surgery, radiation and chemotherapy (multi modal approach) has enabled many patients to achieve cure.  Presently this is what is followed in all cancer hospitals, where tumor board meetings are conducted regularly and new cases will be examined and discussed by all Oncology  Specialities before treatment is advised.

Treatment for cancer can be either local or systemic.  Local treatments affect cancer cells in the tumor and the area near it.  Systemic treatments travel through the blood stream, reaching cancer cells all over the body. Surgery and radiation therapy are types of local treatment.  Chemotherapy, hormone therapy and biological therapy are examples of systemic treatment.

In the treatment of cancer harmful effects on healthy cells are inevitable, these are what doctors describe as side effects. The side effects of cancer treatment depend mainly on the type and extent of the treatment. The side effects will be different for different persons and they may change for a person from one treatment to the next.  A patient’s reaction to treatment is closely monitored by physical exams, blood tests, and other tests.  Doctors and nurses can explain the possible side effects of treatment, and they can suggest ways to reduce or eliminate problems that may occur during and after treatment.

Surgery

Surgery is therapy to remove the cancer by knife; the surgeon may also remove some of the surrounding tissue and lymph nodes near the tumours.  Sometimes surgery is done on an outpatient basis, but many a times patients have to stay in hospital.  Many advances in Cancer Surgery has taken place over the past 2 decades.  Modern anesthetic techniques has greatly increased the safety of major Cancer Surgeries, even in people who are old. Unlike in previous years cancer surgeons for most cancer sites are now emphasizing on organ and function preservation.  Organ and function preservation is now possible in cancer breast, Head and neck cancer, extremity bone and soft tissue sarcoma, anal/rectal cancer, etc.

Radiation therapy

This treatment uses high energy rays to kill cancer cells.  In few cancers, radiation therapy alone may be used instead of surgery as the primary treatment. Radiation therapy also may be given before surgery to shrink a tumor, so that it is easier to remove.  In other cases, radiation therapy is given after surgery to destroy any cancer cells that may remain in the area.

Two forms of radiation therapy are routinely used. Some of patients receive both.

1. External                    2. Internal.

External Radiation therapy

External radiation comes from a machine that aims the rays at a specific area of the body.  Most often, this treatment is given on an outpatient basis in the hospital or clinic.  There is no radioactivity left in the body after the treatment. Many advances have occurred in external radiation treatment, especially over the past 2 decades. High energy x-ray machines called Linear Accelerators have been devised.  These machines are versatile and they can in addition to generation of x-rays can also produce electrons.  Hence, both superficial and deep seated tumors can be treated with minimal damage (side effects) to normal structures.  Moreover, computer assisted, treatment planning systems enable precise targeting of the intended anatomical region again reducing the dose received by normal tissues. As more normal tissues are spared, higher radiotherapy dose delivery is possible increasing the likelihood of cure and recovery from cancers.  The present machines are even better have multi-leaf collimators and hitech computers to totally control the treatment, a area of cancer of any shape can be followed and rapidly treated minimizing treatment time and setup time (Conformal and intensity modulated radiotherapy).

Conformal Radiotherapy – Intensity modulated radiotherapy (CRT/IMRT)

CRT/IMRT makes it possible to treat tumor accurately while avoiding sensitive organs in close proximity.  This is intended to improve the outcome of treatment reducing the adverse effects of treatment to minimum.  IMRT technique allows the doctor to improve local tumor control and decrease adverse side effects of the treatment.  The treatment was designed using inverse treatment planning on the special treatment planning systems, allowing higher radiation dose to be given to the tumor bed minimizing dose to radiation sensitive organs.  The Linear Accelerator is equipped with a multileaf collimator MLC which shapes and modulates the intensity of the radiation beam during the treatment. The  complex sequence of movements of the MLC is calculated on the treatment planning system and transferred electronically to the control system of the linear accelerator.

In IMRT the treatment radiation beams are divided into a series of small fields whose irregular shape in determined by the MLC.  Accurate modeling of the combined effect of many small, irregular fields in order to provide uniform concentrated dose to the tumor is done by computerized systems and treatment executed by the Linear Accelerator. This is a major step towards the routine application of radiotherapy.

Stereotactic radiosurgery/Stereotactic radiotherapy

In situations like brain tumors specialized radiotherapy techniques like stereotactic radiosurgery and stereotactic radiotherapy are offered.  Here in a single session or multiple sessions, pencil shaped beams of radiation are used to treat the disease site.  A high degree of conformality is achieved through beam shaping using accessories like head frames, localizer and 3D Treatment Planning System etc.

Internal Radiation therapy

With internal radiation (also called implant radiation, interstitial radiation or brachytherapy) the radiation comes from radioactive material that is sealed in needles, seeds, wire or catheters and placed directly in or near the tumour. Internal radiation is done by now fully computer controlled Brachytherapy machines. (High Dose Rate/Low Dose Rate). High Dose Rate is preferred especially in developing countries. Internal radiation treatment is safe and in most cancer centers are done on outpatient basis.

High Dose Rate Brachytherapy

High Dose Rate Brachytherapy  in a time tested and safe method that allows physicians to treat cancer with greater precision and less trauma to patient.  The procedure gives physicians and patients the significant advantage of applying a higher dose of radiation directly to the tumor while sparing healthy tissues and surrounding organs.  As a result, this course of treatment is much shorter and more compliant than other cancer treatments and is often performed as an outpatient basis.  Precise dosage of radiation as prescribed by physicians is automatically delivered through using applicators which are positioned in the body.  The hospital staff are monitoring the treatment and maintain contact with you throughout the procedure.  The treatment is safe and painless.  After your treatment, the system removes  the radioactive source into the protective storage unit of the remote after loading machine.  Depending on the treatment site, you should be able to return home and  resume normal activity immediately following your treatment.  The treatment normally requires no special dietary considerations/pretreatment preparations.

Chemotherapy

Chemotherapy is the use of drugs to kill cancer cells.  The doctor may use one drug or a combination of drugs.  Chemotherapy may be the only kind of treatment a patient needs or it may be combined with other forms of treatment. Chemotherapy may be given before surgery or radiotherapy to shrink a tumor or may be given after surgery or radiotherapy to help prevent the cancer from recurring. Chemotherapy is usually given in cycles – a treatment period (one or more days when treatment is given) followed by a recovery period (several days or weeks), then another treatment period and so on.  Most anticancer drugs are given by injection into a vein, some are injected into a muscle or under the skin and some are given by mouth.  Often patients who need many doses of IV chemotherapy receive the drugs through a catheter placed in large vein (a think, flexible tube) that stays in place until treatment is over.  Patients and their families are taught how to care for the catheter and keep it clean.

Anti cancer drugs are also given in other ways.

Intraperitoneal – drugs are placed directly into the abdomen.

Intrathecal – drugs are placed directly into cerebro spinal fluid.

Usually patients have chemotherapy as outpatient.  However depending on which drugs are given, the dose, how they are given, and the patients general health a short hospital stay may be needed.

At present, nearly 50 anticancer drugs are available for treatment, some cancers are cured with only chemotherapy Example, childhood leukemias, Hodgkin’s lymphoma and non Hodgkin’s lymphoma, germ cell tumors, etc.

The side effects of chemotherapy depends mainly on the drugs and the doses the patient receives. As with other types of treatment, side effect  vary from person to person.

Blood cells are most affected, cells that fight infection, help the blood to clot and carry oxygen to all parts of the body are affected. So patients are predisposed to infections, bleed easily and feel tired. Side effects include hair loss, poor appetite, nausea and vomiting, diarrhea, fever or mouth and lip sores. Genetic Engineering has helped us to produce special drugs called colony stimulating growth factors (G CSF, GM CSF)  to overcome the side effects on blood cells. This is allowing more patients to receive/complete the planned chemotherapy protocols.

Some anti cancer drugs can cause long term side effects such as loss of fertility, this may be temporary or permanent, depending on the drugs used and the patients age and sex.

Hormone therapy is used against certain cancers that depend on hormones for their growth.  Example breast cancer, prostate cancer – hormone therapy keeps cancer cells from getting or using the hormones they use.  This treatment may include the use of drugs that stop the production of certain hormones or that change the way they work.  Compared to chemotherapy or radiation therapy, side effects are few with hormone treatment.

Biological therapy (also called immunotherapy) helps the body’s natural ability (immune system) to fight disease or protects the body from some of the side effects of cancer treatment.  Monoclonal antibodies, interferons, interleukins  and colony stimulating factors are some types of biological therapy.

Some of the diseases which had no effective treatment are now responding satisfactorily to biological therapy. (renal cell carcinoma, melanoma, etc).

Bone marrow transplantation

BMT or PSCT (peripheral stem cell transplantation) may also be used in cancer treatment.  The transplant may be autologous (the person’s own cells that are stored earlier), allogenic (cells donated by another person), or syngenic (cells donated by a identical twin).  Both BMT and PSCT provide the patient with healthy stem cells that can home into bone marrow space of patient and start functioning to produce all the blood cells. Before infusion of stem cells, patients are treated with high dose chemotherapeutic drugs to kill all cancer cells, to cause immune suppression and create space for the stem cells to home into recipients bone marrow.

Concern for patients as well as for doctors are the side effects associated with established anti cancer treatments.  Cancer researchers have found out sub cellular and molecular mechanisms of cancer causation and hence treatment approaches are now directed to target these molecular and sub cellular dysfunctions – there include, use of specific monoclonal antibodies, antisense oligoneucleotide therapy, gene therapy, anti angiogenesis therapy, vaccine therapy etc. Most of future lies in these treatments as they are supposed to be having minimal or no side effects and are aimed at root molecular cause of cancer.

Apart from the basic treatments given to cancer patients, ancillary treatments are always necessary like:

Nutrition during treatment

Control of pain

Rehabilitation

Psycho social counseling

Support services

Follow-up of cancer

After cancer treatment is over, it is important for people to continue to have examination regularly.  This ensures that any change in health are identified, and if the cancer recurs, it can be treated as soon as possible.  Follow-up care include a careful physical examination, lab tests, imaging procedures, endoscopies, etc.

Clinical Trials:  (Research studies in which people take part voluntarily)

Clinical trials offer important treatment option for many people with cancer. Research studies evaluate promising new therapies and answer scientific questions.  The goal of such trials is to find treatments that are more effective in controlling cancer with fewer side effects. Cancer specialists normally advice only standard treatment approaches to patients.  But in few patients, cancer has to be treated on a clinical trials. These include studies of ways to prevent, detect, diagnose and treat cancer, studies of the psychological effects of the disease and studies of ways to improve comfort and quality of life.

People who take part in clinical trials have the first chance to benefit from new approaches.  They also make important contributions to medical science. Although clinical trials may prove some risks, researchers take very careful steps to protect people who take part. People who are interested in being part of a clinical trial should consult with their doctor.

Dr. RAMANUJAM A. S.
E-mail: ramanujam1@lycos.com

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