LEARN ABOUT CHEMOTHERAPY

Chemotherapy is a word which generates as much (or probably more) fear than cancer. Patients willingly undergo complicated surgeries for cancer but when it comes to chemotherapy, they develop cold feet. There have been instances when patients have refused cancer treatment because it involved chemotherapy. Some believe that it is an unnecessary treatment but is forced on to patients by us `Modern, new-age doctors’. Scores of `Second opinions’ are sought to find out whether chemotherapy can be avoided. Patients who accept it do so with a fair amount of reluctance.
Chemotherapy- as the word implies- is chemicals used for treatment (chemo- chemicals, therapy- treatment). Though this can apply to most drug treatments, it is an unsaid understanding that chemotherapy means drug treatment of cancer. It is true that in the so-called new age chemotherapy has evolved into an ultra-sophisticated treatment but the concept is not new at all. Paul Ehrlich coined the term `Chemotherapy’ in the 19th Century. Lissauer published his experience of using Arsenic for treatment of Chronic Myeloid Leukemia (a type of blood cancer) in 1890.
In 1945, a ship carrying some chemicals (? for biologic warfare) met with an accident at the Bay of Bari, Italy. The affected sailors had some strange side-effects- hair loss, significant drop in their blood counts and oral ulcers. A committee headed by Dr Goodman and Dr Gilman identified the toxic element- Nitrogen Mustard- and `modern-day’ chemotherapy was born. With the advances in technology and molecular biology, a lot of improvements have happened over years and the newer chemotherapy drugs are more effective with lesser side-effects.
Why does chemotherapy cause so many side-effects? Chemotherapy is designed to kill cells which are rapidly dividing. Different drugs target different pathways in the cell’s life-cycle but all of them bring about the same result- death of the cell. Chemotherapy works better on cells which are dividing faster. Unfortunately, some normal cells in our body also divide rapidly and consequently, are killed by chemotherapy. White Blood cells, cells lining the oral cavity, cells lining the hair follicles are some examples of fast-growing cells. Naturally, these cells get hit by chemotherapy and patients suffer from side-effects like hair-loss, oral ulcers and low white blood cell count.
Any chemical- a drug, chemotherapy or otherwise- usually has more than one effect. The desired effect is taken as `real effect’ and the other effects are thought to be `side-effects’. Actually, the mechanism by which the chemical causes effect is the same which also causes the so-called `side-effect’. For example, drugs like Aspirin, Ibuprofen are used as pain-killers (`desired effect’). But these drugs can also cause hyperacidity and ulcers in the stomach and heartburn (`side-effect’).Pain-relief is brought out by reduction in synthesis of prostaglandins, a chemical which causes inflammation. Prostaglandins also protect the lining of the stomach, so decrease in their production causes all the `side-effects’ in the stomach. So, if one accepts the pain-killing effect of aspirin, one also needs to accept its effects on the stomach. Same is true about chemotherapy. The drugs are specifically created to kill fast-growing cancer cells. If this effect is desired, the other effects of chemotherapy have to be accepted.
There is a difference between `side-effect’ and `adverse-effect’ which needs to be clarified at this point. A side-effect becoming worse, more severe or complicated is an adverse effect. A reduction in white blood cells is a `side-effect’. But this low cell count causing a serious infection is an adverse effect. Nausea may be a side-effect but severe vomiting with dehydration is an adverse effect. The treating team strives to prevent adverse effects and reduce the severity of side-effects.
New chemotherapy drugs are specifically engineered keeping the above distinction in mind. Targeted therapy is a novel form of chemotherapy. Many of the old drugs targeted one pathway or the other but the drugs were designed first and the targets were discovered later. In today’s targeted therapy, the target is preselected and the drug is designed accordingly. So, the chances of `mis-hits’ are reduced and the efficacy is increased. Some of the drugs target such intricate mechanisms that the cancer cells may not be killed but their functioning is hampered so that they do not divide and the body’s immunity can destroy them.
Most chemotherapy drugs cause some side-effects immediately after administration. Drugs like Paclitaxel or Rituximab, while being infused may cause allergic reactions ranging from simple rash to a life-threatening reaction. This can be prevented or treated by administering steroids like Dexamethasone. Apart from this, most chemotherapy drugs do not cause any major problems while being administered.
Today, most drugs are given through an intravenous line (through saline). While starting the intravenous drip, a cannula is inserted into the patient’s vein. This is the only time when the patient feels the `pain’ of chemotherapy. Apart from this the patient does not feel pain anytime during the chemotherapy infusion. That chemotherapy is a `painful’ process is a myth which should be disregarded.
Nausea and vomiting is a common side-effect of many drugs including chemotherapy. Most chemotherapy regimens have adequate provision for preventing this side-effect. In the `70s and `80s, this side-effect was particularly fearsome as highly emetogenic drugs like Cisplatin and Doxorubicin came to the fore and there were no effective medicines against their side-effects. But after the availability of Ondansetron (and now Granisetron and Palonosetron)vomiting due to chemotherapy has been curtailed significantly. Most patients develop nausea (a feeling of vomiting and stomach being upset) and only few actually develop vomiting. Some of these drugs used to treat nausea and vomiting may cause constipation, usually 2-3 days after chemotherapy. This may suppress appetite in some patients.
Around 8th-10th days, patients on chemotherapy may experience reduction in their White Blood Cell (WBC) count which in turn, may make them vulnerable for infections. Patients suffering from fever during this period should not self-medicate themselves with anti-fever tablets like Paracetamol. Instead, they need to contact their treating team immediately. This fever needs to be treated as a medical emergency and patients often require hospitalization. To prevent this reduction, patients are administered growth factors after chemotherapy.
Mouth sores/ulcers may also develop during this period. These may get infected with bacteria or fungi and this may be an additional cause of fever. In severe cases, the ulcers may prevent eating altogether and such patients may require intravenous fluids and antibiotics.
Hair fall- the most dreaded side-effect of chemotherapy- happens around 17th-18th day. Hair loss is painless- happens all of a sudden during a head-bath and is usually complete. It should be noted that some chemotherapy regimens do not cause hair fall. Hair fall is a disfiguring side-effect but it has no serious medical implications and is completely reversible.
Some chemotherapy drugs (platinum compounds) can affect nerves and cause numbness and tingling sensation in fingers and toes. Some patients may also complain about burning and pain in limbs which may disturb their sleep. This effect may last for several months after chemotherapy. The treating team can prescribe suitable medicines for this effect.
Chemotherapy can cause some delayed effects which may present after months or years. Some drugs (Doxorubicin) may affect the heart adversely and may make it weak. Some drugs may damage the kidney (Platinum compounds) or liver (Doxorubicin/Gemcitabine). Fortunately, these effects are rare.
Though the list of chemotherapy-related side-effects is a long one, most effects are mild and can be treated easily. Almost all effects are temporary and they subside within few days of stopping chemotherapy. Today’s chemotherapy is safe and the side-effects should not deter patients from opting for an effective treatment.

- Oncologist in Pune | Cancer Specialist | Dr. Chetan Deshmukh