COVID-19 effect on breast cancer treatment

By Dr K Govind Babu,

Breast cancer is the second leading cause of cancer death after lung cancer as the most common invasive form in women. It has surpassed lung cancer as the leading cause of global cancer incidence in 2020, with an estimated 2.3 million new cases, representing 11.7% of all cancer cases.

The fatal Covid-19 that turned into a global pandemic in the year 2020, has affected every aspect of life, including screening, diagnosis, and treatment of other diseases. People with cancer especially have found themselves in a difficult and frightening situation ever since the pandemic began. Covid-19 has since been associated with multi-organ failure due to immune-mediated damage. Immune compromised people, such as cancer patients, are not only at increased risk of SARS-CoV2 infection, but also of severe infection and poor prognosis or fatality. So many people have been found delaying the screening and treatments.

A recent report published by National Cancer Registry Programme (NCRP) estimates that the number of cancer cases is likely to increase from 13.9 lakh in 2020 to 15.7 lakh by 2025, an increase of nearly 20%. Covid- 19 has impacted breast cancer patients by not only increasing the chances of infection but also on the treatment associated with breast cancer.

Keeping in mind the COVID-19, surgical procedures are delayed in order to use the available healthcare resources where they are most needed. There are numerous changes to treatment regimens, which reduces the amount of time patients spend in treatment centres.

Minor forms of surgeries with breast reconstruction are alternatives to complete removal of breast for the treatment of breast cancer in the curative setting. As per global recommendations, the risk-benefit balance clearly favours maintaining medical treatment and thus the recommendation is that standard indications, regimens, and doses of adjuvant/neoadjuvant systemic therapies should always be followed. Neoadjuvant therapies are delivered before the main treatment, to help reduce the size of a tumour or kill cancer cells that have spread. 

Adjuvant therapies are delivered after the primary treatment, to destroy remaining cancer cells. Systemic adjuvant or neoadjuvant therapies, including chemotherapies, have been shown to be related with an increased risk of severe SARS-CoV-2 infection sequelae. When appropriate, duration of treatment should be shortened to decrease the number of hospital visits, but in other instances treatment duration should be maintained to avoid increasing the risk of immunosuppression depending on the clinical condition of patients. Conventional adjuvant/neoadjuvant systemic medications, such as anti-human epidermal growth factor receptor 2 and endocrine therapy, have historically not been related with problems of COVID-19, and hence should be used according to the guidelines. 

Some women have breast tumours with higher levels of a protein known as HER2 – these are called HER2-positive breast cancers. HER2 is a growth-promoting protein on the outside of all breast cells. Breast cancer cells with higher-than-normal levels of HER2 are called HER2-positive. These cancers tend to grow and spread faster than other breast cancers but are much more likely to respond to treatment with drugs that target the HER2 protein like trastuzumab and pertuzumab. There is now good clinical evidence demonstrating that in patients with human epidermal growth factor receptor 2 positive breast cancer, trastuzumab and pertuzumab targeted therapy is extremely effective. This is categorised as a category 1 treatment for HER2 +ve therapy according to NCCN guidelines. When trastuzumab is added, pertuzumab can mediate antibody-dependent cellular cytotoxicity (ADCC) and may further enhance body cells’ immune response to kill the cancer. 

In today’s COVID crisis, where biologics are preferred therapy due to less immune suppression, the use of biosimilars that cause immunological reactions raises the likelihood of COVID infection and exposes patients to greater disease severity. As a result, not only should the overall management of breast cancer patients prioritise biologics over chemotherapy and avoid biosimilars with questionable clinical data.

(The author is Medical Oncologist, St. John’s Medical College & HCG Hospital. The article is for informational purposes only. Please consult medical experts and health professionals before starting any therapy, medication and/or remedy. Views expressed are personal and do not reflect the official position or policy of the Financial Express Online.)