Background

Chemotherapy is one of the main treatments currently used to treat cancer using a variety of drugs. Unfortunately, whilst killing cancer cells, healthy cells can become damaged too, thus resulting in a variety of side effects ranging from fatigue and hair loss to chemotherapy brain fog, sex, and fertility issues. 

Read on to learn more about the above-mentioned side effects of chemotherapy as well as others including those with immediate and long-term lasting effects, why they may occur, and how they could be effectively managed and treated. 

Introduction

Chemotherapy¹ or ‘’chemo’’, as it is commonly referred to, is a type of cancer treatment that involves the use of drugs to kill tumour cells and prevent further tumour growth. Tumours are a lump of abnormal cells that can become cancerous (malignant). 

Although the main purpose of chemotherapy is to target and destroy cancer cells, it can also kill and destroy healthy, normal cells in the process, in turn resulting in a wide range of side effects in most patients. However, it is important to note that some people who undergo chemotherapy do not experience any side effects. Whether or not a patient experiences side effects from chemotherapy depends primarily on their overall health and the types of drugs used throughout treatment. The use of chemotherapy alone or in combination with other cancer treatments such as radiation therapy can also have a significant impact on a patient’s overall outcome from chemotherapy.¹

Immediate side effects

Nausea and vomiting 

Current research studies suggest nausea and vomiting be the most common side effects experienced from chemotherapy, with over 79.3% of patients reporting this side effect.²

Nausea and vomiting caused by chemotherapy are referred to as chemotherapy-induced nausea and vomiting (CINV).

Multiple types of CINV occur before, during, or after chemotherapy treatment. The main types of CINV include:

• Acute CINV: occurs minutes to hours after chemotherapy administration

• Delayed CINV: occurs 24 hours following chemotherapy administration
• Chronic CINV: persists for a long time even after chemotherapy treatment ceases
• Anticipatory CINV: occurs before chemotherapy administration. It occurs when patients who previously had chemotherapy, sense smells, sights, or sounds (hence anticipatory) that remind them of their previous chemotherapy treatment experience, and in turn, trigger CINV
• Breakthrough/refractory CINV: occurs after taking medications to relieve nausea and vomiting.³ 

Causes 

According to research studies, chemotherapy drugs can cause CINV by activating 5-hydroxytryptamine 3 (5-HT₃) receptors in the brain called the chemoreceptor trigger zone (CTZ).

Management and prevention 

At present, CINV can be managed and treated using the following strategies: 

• Mindful eating: patients experiencing CINV are recommended to practice mindful eating by:
  • Eating small meals regularly throughout the day to prevent nausea
  • Drinking and chewing food slowly to reduce the risk of vomiting
• Well-planned eating schedule: it is recommended for patients experiencing CINV to postpone their eating straight before or after cancer treatment to prevent nausea
• Rest and relaxation: incorporating rest after eating as well as relaxation techniques such as self-hypnosis can help alleviate symptoms of nausea
• Medications: a variety of medications are currently used to treat CINV, with the main being shown below:³
  • 5-HT3 receptor antagonists such as ondansetron, granisetron, dolasetron, and palonosetron
  • NK1 receptor antagonists such as aprepitant, and fosaprepitant
  • Corticosteroids such as dexamethasone. Corticosteroids are especially helpful in preventing and treating both acute and delayed CINV
  • Dopamine receptor antagonists such as phenothiazines (e.g. prochlorperazine), butyrophenones (e.g., haloperidol, and droperidol), and substituted benzamides (e.g. metoclopramide). Dopamine receptor antagonists are usually prescribed for patients with breakthrough/refractory CINV
  • Benzodiazepines such as lorazepam and alprazolam

Fatigue

Fatigue is another common immediate side effect reported to affect over 74.7% of patients receiving chemotherapy.⁴

Causes 

During chemotherapy, the body works harder than usual not only to fight cancer but also to repair the damage done to healthy, normal cells which puts strain on the body, thus resulting in fatigue.

Many chemotherapy drugs can also decrease the number of red blood cells and lead to anaemia due to insufficient oxygen around the body.⁵ 

Management and treatment 

To effectively manage and treat fatigue induced by chemotherapy, the following strategies are recommended: 

• Keep a diary of your energy levels: to better plan your days and tailor your activities depending on your energy levels
• Prioritise daily activities: especially on days when energy levels are very low
• Find a good balance between rest and physical activity: make sure to balance physical activity with rest so that you are not expending too much energy, but also not remaining completely sedentary (inactive) as both factors can exacerbate fatigue
• Eat a healthy, nutritious, balanced diet rich in fruit and vegetables: to keep blood sugar levels stable and thus prevent fatigue 
• Lower stress levels: by practicing relaxation techniques regularly such as deep breathing, meditation, and gentle yoga 

Hair loss 

Hair loss is a third major immediate side effect of chemotherapy, affecting over 60% of patients.⁴ Fortunately, hair loss from chemotherapy is often only temporary and hair usually grows back two to three months after chemotherapy. 

Causes

Chemotherapy can destroy hair follicles which are responsible for hair growth and hair texture, thus resulting in hair loss. 

Management and treatment 

To effectively manage and treat hair loss caused by chemotherapy consider the following: 

• Planning your new look: plan what outfits you might use to cover your hair including scarves, hats, or headwraps. If considering wearing a wig, plan, and research which type you might purchase to better match your hair’s texture and colour 
• Avoid hair care practices that can damage and dry out hair including:
  • Washing hair too often 
  • Use heat styling tools such as blow dryers, curlers, hair straighteners, and curling irons multiple times a week

Loss of appetite 

Over 65.5% of patients receiving chemotherapy have been reported to experience loss of appetite as a side effect.⁴ 

Causes

Chemotherapy can cause loss of appetite due to a variety of reasons including: 

• Changes in the sense of taste: chemotherapy can cause foods to have an overall metallic taste that makes eating unenjoyable
• Mouth sores and sore throat: these can make chewing and swallowing food very painful 

Loss of appetite can also occur in some patients who experience CINV. 

Management and treatment 

The following strategies can help manage and treat loss of appetite from chemotherapy:

• Experimenting with different flavours and recipes: using different herbs, spices, condiments, and dressings to add more flavour to foods and make eating more enjoyable
• Treating mouth sores: eating foods that are generally soft and avoiding fizzy drinks, crunchy, and acidic foods as these can irritate the mouth and worsen mouth sores 

Diarrhoea

In addition to nausea, vomiting, fatigue, and hair loss, chemotherapy may also cause immediate gastrointestinal (GI) side effects such as diarrhoea.^6,7 If not effectively managed, diarrhoea can result in dehydration and malnutrition. 

Causes 

Chemotherapy can weaken and damage the lining of the GI tract, thus resulting in loose watery stools characteristic of diarrhea. Certain chemotherapy drugs can also temporarily cause lactose intolerance which may result in diarrhoea when dairy products are consumed. 

Management and treatment 

Chemotherapy-induced diarrhoea can be managed and treated by: 

• Drinking a minimum of six 8-ounce glasses of fluid per day
• Avoiding certain foods that may cause GI distress including:
  • Dairy products, especially if they cause symptoms of lactose intolerance
  • Gas-inducing foods such as cabbage, broccoli, corn, and peas
  • Fatty, fried, or spicy foods

Long-term and late effects

Cognitive effects

In addition to immediate side effects, chemotherapy can result in severe long-term side effects that may persist long after chemotherapy ceases. 

Chemotherapy brain fog 

One of the main long-term side effects of chemotherapy is chemotherapy brain fog or ‘’chemo brain’’, as it is more often referred as. ‘’Chemo brain’’ is a type of chemotherapy-induced cognitive impairment that causes difficulties with concentration, memory, and thinking. Patients with chemotherapy brain fog can take longer than usual to think, process, remember, or retain certain information. 

Management and treatment 

Chemotherapy brain fog or ‘’chemo brain’’ can be managed and treated by:

• Getting sufficient sleep: eight hours per day is ideal
• Exercising both the body and the mind regularly: by engaging in light, daily exercise as well as puzzles, mind games, and reading 
• Taking note of important events 
• Staying organised and planning 

Sex and fertility issues 

Causes 

Many of the side effects experienced from chemotherapy such as fatigue and poor body image due to hair loss and weight changes, for example, can decrease the quality of sex life and even the chances of pregnancy. 

Chemotherapy can also negatively impact sex and fertility by lowering levels of certain hormones that are necessary for fertility including 

• Estrogen in people assigned female at birth (AFAB): this in turn can result in conditions that cause infertility such as primary ovarian insufficiency
• Testosterone in people assigned male at birth (AMAB): in addition to lowering testosterone levels, chemotherapy can also lower sperm count in people AMAB which can make conceiving a challenging process 

Management and treatment 

To manage and treat sex and fertility issues caused by chemotherapy, consider using certain techniques to either:

• Assist reproduction such as in vitro fertilisation (IVF) or intracytoplasmic sperm injection
• Preserve fertility such as sperm banking or cryopreservation

Summary

Chemotherapy works by targeting and killing cancer cells and preventing further tumour growth using various drugs. Unfortunately, whilst doing this, chemotherapy can damage and kill healthy, normal cells too, thus resulting in side effects in most patients.

The side effects experienced from chemotherapy may be immediate or long-term. 

The most common immediate side effects of chemotherapy include:

• Nausea and vomiting (CINV)
• Fatigue
• Hair loss
• Loss of appetite 
• Diarrhea 

On the other hand, the most common long-term side effects of chemotherapy include:

• Chemotherapy brain fog or ‘’chemo brain’’
• Sex and fertility issues 

Many of the side effects of chemotherapy can be effectively managed and treated by:

• Planning and staying organised
• Eating well
• Taking prescribed medications
• Sleeping enough
• Managing stress 

However, it is important to speak to your healthcare provider if you experience any of the side effects of chemotherapy discussed in this article or others to provide you with the best management and treatment options for you.