Angelina Jolie, who has undergone double mastectomy after a test revealed she was at high risk of breast cancer
New Delhi, March 19: Women with early stage breast cancer that has just started to spread are less likely to suffer a recurrence or die from the disease if they receive radiotherapy after mastectomy, a new research study has shown.
The study by an international team of researchers seeks to resolve a debate whether radiotherapy can help women who have early stage breast cancer that has spread only to one, two or three of their lymph nodes.
Most breast cancer treatment guidelines prescribe radiotherapy after mastectomy only to women whose cancer has spread to four or more lymph nodes --- because studies have clearly established that adding radiotherapy helps reduce recurrence and mortality in this set of women. But until now there has not been enough evidence to recommend radiotherapy to women with limited spread of cancer.
“We’re hoping this new study will influence clinical practice and help reduce the number of women dying from breast cancer,” Carolyn Taylor, a clinical oncologist at the University of Oxford and a member of the research team, told The Telegraph.
The researchers pooled data from 22 earlier trials mainly in Europe and North America involving 8,135 women with breast cancer with or without spread to their lymph nodes who had received mastectomy, radiotherapy or chemotherapy or some combinations of these.
Their analysis, Taylor said, has shown the benefits of post-mastectomy radiotherapy in both sets of women — those whose cancer had spread to four or more lymph nodes and those whose cancer was restricted to one, two or three lymph nodes.
Among 1,314 women who had cancer in one to three lymph nodes, those who received radiotherapy after mastectomy had 32 per cent lower recurrence and 20 per cent lower mortality. Radiotherapy led to 12 fewer recurrences of breast cancer in every 100 women after 10 years. The results of the study were published today in The Lancet, a medical journal.
“These are highly significant results,” said Vinod Raina, a senior oncologist at the Fortis Memorial Research Institute and Hospital in Gurgaon who had participated in the study’s steering committee meetings but was not directly involved in it.
While the benefits of radiotherapy had been established for women with the involvement of four lymph nodes, Raina said it was not clear whether this strategy also yields similar benefits to women with smaller number of nodes.
“But over the past four or five years, some oncology centres have been prescribing radiotherapy to this set of women (with less than four lymph nodes),” Raina told this newspaper. “These new results will help consolidate this practice.”
The study observed the benefits of post-mastectomy radiotherapy regardless of whether the patients in the trials had or had not received chemotherapy or hormone therapy that is sometimes part of managing early stage breast cancer.
“By assimilating results from multiple trials, we’ve reduced the effects of chance and get reliable results,” said Paul McGale, a senior statistician and team member at the Clinical Trials Research Unit at the University of Oxford.
The evidence shows that radiotherapy after mastectomy significantly reduces the risk of recurrence of breast cancer which, McGale told this newspaper over the telephone, translates into lower risk of dying from the disease.
Breast cancer has emerged the most common cancer among women in several Indian cities, including Bangalore, Calcutta, Chennai, Delhi and Mumbai and the second most malignancy after cervical cancer in rural areas.
A cancer registry maintained by the Indian Council of Medical Research suggests that breast cancer accounts for nearly one-fourth of cancers in women in some Indian cities.
McGale will present the results of the study at the European Breast Cancer Conference in the UK on Thursday.
The 22 trials the study examined had been initiated between 1964 and 1982. Improvements in radiotherapy delivery techniques over the past two decades are likely to increase the proportional benefits to patients. However, improvements in chemotherapy during the same period could make the absolute gains in reduced risk of recurrence and mortality appear slightly smaller.