A pioneering national study carried out in the UK looked at the 30-day mortality rate of breast cancer and lung cancer patients who were undergoing systematic anti-cancer therapy (SACT) in NHS Trust during 2014.
It found out that 8.47% lung cancer patients (1,274 out of 15,045) and 2.47% breast cancer patients (700 out of 28,364) couldn’t even survive for a period of a month after receiving one or more cycles of chemotherapy treatment.
The data was gathered from the Public Health England’s SACT dataset. It was jointly conducted by experts from the PHE and St James Hospital, Leeds, UK. Pertinent figures in lung cancer patients and breast cancer patients – 1,274 out of 15,045 and 700 out of 28,364, respectively, depicted high mortality after one month of treatment.
Chemotherapy runs in the forefront of cancer treatment and its role has evolved in the field of oncology over the last four decades. Although used primarily to kill the tumor cells and help contain these malignant cells from metastasis, the collateral damage of chemotherapy to the healthy cells is often not discussed.
However, this particular study has broken the norms and analyzed how hazardous chemotherapy can be. These striking findings from the study were also published The Lancet Oncology journal on 30th August.
The study also looked at the confounding characteristics of the patients such has their overall health, age, sex and BMI in relation with the chemotherapy outcomes. Interestingly, the stage of cancer and person’s resilience against the drug had a direct association with the mortality rate.
In connection with this, the mortality was higher for patients who were receiving SACT as palliative treatment which was 10% for lung cancer patients and 7.48% for breast cancer patients, as compared to the mortality rate of cancer patients who received it as curative treatment, which was 2.88% for lung cancer patients and 0.26% for breast cancer patients.
The stark difference should make the oncologists contemplate upon the cancer treatment given to the patients who are at the last stage of their cancer which has spread to other organs. For patients at advanced stage of cancer, their resilience and overall health deteriorate to the extent that chemotherapy stops to be of any help to them.
With an insight into the impact of chemotherapy on the health of cancer patient, the study also went on to say that the mortality rates were higher for both palliative and curative patients who were receiving chemotherapy treatment for the first time as compared to those who had already went to chemotherapy treatment cycles.
Similarly, the mortality increased with the age of the patient in both lung cancer and breast cancer patients. On the contrary, the mortality rate decreased with the age of patients receiving palliative SACT. It was inferred that this trend was observed because the cancer in younger patients was more aggressive in nature and the older patients preferred other cancer treatment over chemotherapy.
Chemotherapy was offered for certain types of cancers in the beginning but later it was used for many other types of cancer as well. Chemotherapy drugs come from a diverse class of backgrounds which unify at their task of inhibiting the growth of cancer cells, as they target different phases of the cell cycle of these rapidly growing tumor cells.
More than a 100 chemo therapy drugs are marketed today which target various types of cancer differently.
However, their limitation is that they cannot differentiate between healthy cells and cancer cells, due to which weak patients do not respond well to them and consequently have adverse effects of the drug on their ailing health.
Among the chemotherapy drugs, the most commonly used drug categories include alkylating agents, antimetabolites, topoisomerase inhibitors, mitotic inhibitors, anti-tumor antibiotics and corticosteroids. Alkylating agents damage the cellular DNA and limit the cellular proliferation of cancer cells. As these drugs directly cause DNA damage, they are likely to affect bone marrow which inevitably damages the blood cells.
The antimetabolites drugs disrupt the RNA and DNA sequences of the tumor cells to limit cell proliferation. Topoisomerase inhibitors are enzyme inhibitors that are crucial cell replication. Similarly, as the name suggests, the mitotic inhibitors control the tumor cells from dividing, while the anti-tumor antibiotics interfere with the replicating machinery of tumor cells and hinder their growth. Steroids are hormones administered with other chemotherapy drugs to prevent allergic reactions.
In additional to damaging the healthy cells and their genetic information, chemotherapy is also known to increase blood clotting factors in cancer patients, which results in death by a condition known as thromboembolism. Thromboembolic events lead to further medical complications which include myocardial infarction, strokes, cardiac arrest and severe infections. These infections are also a result of low white blood cell count after receiving chemotherapy.
With the new diagnosis techniques and preventive cancer management, it is preferred that the oncologists look for better treatments and come to chemotherapy as their last resort, because the side effects are often outweighed by this benefits.
Dr Jem Rashbass, Cancer Lead for PHE, said, “We are privileged in England to have access to such high quality cancer data. This world-leading database will allow us to monitor the quality of chemotherapy treatment given to all patients across the NHS in near real-time.”
It is now hoped that, better cancer management interventions will be brought forward in future and similar quantitative studies will be carried out in other countries to reflect back at the efficacy of chemotherapy. This in turn will assist experts to weigh out the advantages of chemotherapy drugs over the incurred health damage and invested time and resources.