VERIFIED CONTENTAuthor: Katarzyna Wieczorek-Szukała, MD, PhD, medical biotechnologist, Medical University of Lodz

"Yellow chemistry" is a common term for one form of adjuvant treatment used in breast cancer. It usually consists of 3 drugs: methotrexate, cyclophosphamide and 5-fluorouracil. The name comes from the color of the container with their mixture, where the yellow color is mainly due to methotrexate. How does this type of cancer therapy work and what are the side effects?

"Yellow chemistry" is one of the terms used by doctors in relation to oncological treatment. In the community of cancer patients and oncologists, apart from chemical names and specialist jargon, people sometimes use colloquial names referring to the color of the administered drugs. Chemotherapy is very often administered intravenously - as a series of single injections or the so-called drip infusion, administered slowly, even over a dozen hours. The mixture placed in a dispenser or in a syringe usually contains a "cocktail" of several cytostatics, the complementary spectrum of which is to ensure the best possible effect in eliminating cancer cells.

Colors of chemotherapy

There are 3 main colors of chemotherapy:

  • Red chemistry - one of the most aggressive forms of cancer therapy, most often used in the form of infusions, incl. in leukemia, bladder cancer, prostate cancer. Its bright ruby ​​color is given by doxorubicin - a powerful anthracycline cytostatic. In addition, other drugs may also be present in the solution, e.g. epirubicin or cyclophosphamide.
  • White chemistry - considered less harmful than other forms of chemotherapy, its main ingredient is bleomycin, which when dissolved gives a colorless, clear solution. This cytostat is used, inter alia, in in the treatment of squamous cell carcinoma of the head and neck, external genital organs, cervical cancer and testicular cancer.
  • Yellow chemistry - used as an adjunct therapy in the treatment of breast cancer and administered in cycles as intravenous infusions. The mixture usually contains cyclophosphamide, 5-fluorouracil and methotrexate (which gives the solution an intense yellow color).

Of course, not knowing the exact composition of the administered preparation (only judgingthe color of the infusion), its operation and potential side effects cannot be determined. The recipe and schedule of oncological therapies is always determined individually and consulted with the latest national recommendations and guidelines.

When is yellow chemistry used?

"Yellow" chemotherapy is mainly used in the treatment of breast cancer. Currently, it is the most common malignant neoplasm in women, and the number of detected cases in European countries is growing every year. Unfortunately, this cancer (right after bronchial and lung cancer) is associated with a high mortality rate, which is a huge problem, especially in Poland. In just one year, nearly 10,000 women in our country die of advanced breast cancer.

There are many known risk factors that may influence the development of the disease, some of them, for example :

  • over 35
  • genetic factors (gene mutations: BRCA1, BRCA2, p53, ATM, transmitted e.g. from mother to daughter)
  • hormonal factors (taking hormonal contraceptives or hormone replacement therapy in old age)

Specialists decide which treatment to start in a specific case of breast cancer after thorough diagnostic tests.

It is necessary to classify the detected change according to TNM criteria (from T-tumor; N-nodus (node); M-metastases (metastases)) - a scale that assesses not only the size of the tumor itself, but also the condition of local lymph nodes and the possible presence of distant metastases.

The histological type, the presence of estrogen and progesterone receptors and HER2 receptors are also determined on the basis of the tumor biopsy. All of this is done to identify signals that potentially stimulate cancer cells to grow and to plan the most effective therapy.

Unfortunately, despite the advancement of modern medicine, no prognostic factor or diagnosis can 100% predict the course of the disease in a given patient.

Until recently, the routine treatment of breast cancer was standard surgery involving the removal of the entire breast. Currently, however, this radical method is being abandoned using the so-called conserving surgery (especially if the size of the detected tumor is below 3 cm and no lymph node metastases are found).

To ensure maximum effectiveness of treatment and to be sure that the disease will not come back, chemotherapy is additionally used - strong drugs that inhibit cell proliferation.

This type of systemic therapy can be used before elective surgery (toreduce the tumor mass) or after the procedure - as adjuvant treatment (the so-called adjuvant treatment).

Although almost every form of chemotherapy is extremely harmful to the body, it is not selective and usually causes a number of side effects - in some cases of breast cancer, this type of additional treatment will be required. Such a need will arise, among others when:

  • a cancerous tumor is characterized by a very rapid growth,
  • distant metastases appeared,
  • histopathological analysis revealed the absence of estrogen and progesterone receptors.

Especially the latter trait is a bad prognostic for treatment effectiveness as it means that cancer cells are insensitive to other, more selective treatments, e.g. hormone therapy. Chemotherapy with a broad spectrum of activity (e.g. cytostatics included in yellow chemistry) becomes the treatment of choice.

Ingredients of yellow chemistry

The most commonly used drugs included in the yellow infusion are 3 popular cytostatics:

Methotrexate

This substance was introduced into treatment in the 1950s, but is still included in the list of essential medicines published by the World He alth Organization (WHO).

Methotrexate is called antivitamin (antagonist) of folic acid, which means that it practically irreversibly disturbs all biochemical changes of all derivatives of this compound.

In turn, folic acid performs very complex functions in the body - it participates in the synthesis of amino acids, bases used in the synthesis of DNA and RNA, and is also a "carrier" of one-carbon groups in many reactions.

Methotrexate is a therapeutic agent that not only has anti-cancer properties (inhibiting cell division), but also immunosuppressive (inhibiting the immune system response).

It is used in the fight against neoplastic diseases:

  • acute leukemias (lymphatic and myeloid)
  • nipple cancer,
  • ovarian cancer,
  • lung cancer,
  • solid neoplasms of the head and neck.

Methotrexate can be administered not only in the form of intravenous infusion, but also sometimes orally in the form of tablets. The drug is excreted 90% in the urine.

In much lower doses, methotrexate is also used in the course of autoimmune rheumatoid diseases (e.g. rheumatoid arthritis or ankylosing spondylitis) as the so-called disease-modifying drug (DMARDs).

5-Fluorouracil (5-FU)

5-Fluorouracil (5-FU) is an organic chemical compound and a fluorinated uracil derivative - basebuilding RNA. As a result of its action, the resulting RNA exhibits abnormal structure and impaired function, resulting in cell damage and death. The cytostatic effect of fluorouracil is especially visible in highly differentiated and rapidly growing tissues (e.g. skin, mucous membranes, bone marrow).

5-fluorouracil is most often used in therapy:

  • breast cancer,
  • colorectal cancer,
  • stomach cancer,
  • pancreatic cancer,
  • cervical cancer,
  • ovarian tumors.

In addition to intravenous administration, this drug is sometimes used as an ointment for keratinizing or precancerous skin lesions, where it promotes their healing.

Cyclophosphamide

Cyclophosphamide (also known as a commercial preparation - Endoxan) - is one of the most commonly used cytostatics, successfully used in anti-cancer therapies. An interesting fact is that in terms of chemical structure, it is a derivative of nitrogen mustards - compounds classified as dangerous, stinging poisonous warfare agents.

After administration to the system, it is converted to active metabolites only in the liver. These compounds have characteristic alkylating properties, which consist in transferring chemical groups in the molecules of functional compounds.

Such structural modifications cause permanent damage to proteins, DNA and RNA chains, thus inhibiting proper cell division (especially in rapidly dividing tissues).

Cyclophosphamide is used, inter alia, in in therapies:

  • breast cancer,
  • acute leukemias,
  • multiple myeloma,
  • Malignant Hodgkin,
  • small cell lung cancer,
  • endometrial cancer.

This compound can also be sometimes used in the treatment of severe forms of connective tissue diseases (collagen diseases) with an autoimmune background, such as:

  • rheumatoid arthritis (RA),
  • systemic lupus erythematosus,
  • systemic sclerosis,
  • Sjögren's syndrome.

Like methotrexate, cyclophosphamide can be administered both orally (in tablets) and intravenously as a drip infusion.

Potential side effects of yellow chemistry

Combining the action of 3 strong cytostatics in one preparation of "yellow chemistry" undoubtedly increases the chances of eliminating cancer cells from the body. Unfortunately, this also translates into a greater risk of side effects that are burdensome for patients. Not all people treated will experience similar side effects. The response to treatment depends on many factors, including:

  • ages,
  • body wasting,
  • comorbidities,
  • other medications taken.

Since all three of the listed components of "yellow chemistry" have broad systemic effects, it will be extremely difficult to determine which cytostatic caused any adverse symptom. However, some symptoms appear statistically more frequently in patients than others. What side effects should a patient taking "yellow chemistry" be prepared for?

  • Reduced resistance to infections - both methotrexate, cyclophosphamide and 5-fluorouracil can permanently damage the bone marrow, which is responsible for the production of white blood cells in the immune system (so-called neutropenia). This, in turn, will translate into an increased susceptibility to common colds, but also fungal or bacterial diseases. To prevent your white blood cell count from dropping too much, blood tests are done before each cycle of chemotherapy.
  • Chronic fatigue and weakness - the effect of the cytostatics used is non-selective, which means that they damage both cancerous and he althy cells. The organism of the person undergoing therapy is struggling hard, which in the course of the following cycles translates into its debilitating and weakening feeling. Patients should therefore take particular care of a nutritious diet and rest, and avoid driving a car or operating complex machinery.
  • Vomiting, diarrhea and gastric symptoms - gastrointestinal symptoms are quite common with the use of cyclophosphamide and methotrexate. This is due to the strong action of these substances on the gastrointestinal epithelium, which often causes inflammation of the mucous membranes. Severe symptoms sometimes require additional support with anti-emetic and anti-diarrheal drugs. To prevent dehydration, patients are advised to drink plenty of drinks.
  • Hair loss and alopecia - although it is one of the symptoms with the least significant impact on the global he alth of the body, many people perceive it as the most severe for aesthetic reasons. This symptom is characteristic of the action of all 3 components of "yellow chemistry". Hair thinning usually starts 3-4 weeks after starting treatment and may gradually involve loss of eyebrows and eyelashes or body hair. Fortunately, after the end of therapy, hair grows back - although sometimes it may have a different shade or texture than before.

The listed symptoms are just some of the unpleasant ailments that may occur after a cycle of oncological therapy. In order to win the fight against cancer, however, it is worth facing them.

Category:

Oncology