“Breast cancer in the geriatric population is a major health issue. Of the more than 230,000 new cases diagnosed annually, somewhere between 40% and 50% will occur in women 65 and over. Furthermore, the elderly population has been and will continue to increase exponentially over time,” stated Meena S. Moran, MD, Associate Professor at Yale University in New Haven, Connecticut, who was the invited discussant for these studies. “But because elderly patients are underrepresented in clinical trials, it remains unclear whether the benefits of radiation can be extrapolated to this elderly population.”
And while trials like CALGB 9394 provide data suggesting that overall survival may not be affected in elderly low-risk patients who only take tamoxifen after surgery (without radiation), it is important to recognize that clinically meaningful differences do exist between patients treated in routine practice and those who are treated on clinical trials such as these. Population-based studies allow us insight into practice patterns and treatment trends that are more representative of the general U.S. population.
Three Lessons
Dr. Moran pointed out the lessons we can learn from these studies:
(1) Based on Dr. Cohen’s study, we know that patients who are not receiving radiation (often omitted because patients with comorbidities are perceived as having a shortened life expectancy) are still living more than 11 years.
(2) The omission of radiation therapy in the elderly population has continued to slowly increase since the publication of CALGB 9394 in 2004.
(3) It is highly unlikely that the benefits in survival that were reported in these studies at the ASTRO Annual Meeting can be attributed to radiation alone.
“It is more likely that selection biases, and possibly the inclusion of T2 tumors, are inflating these numbers,” Dr. Moran stated. “Relative to controlled trials, population-based data have inherent selection biases in the treatment delivered, where the patients perceived as likelytolive longer are the ones living longer, and also are more likely to receive radiation. Remember, the Oxford Overview only showed a 3% benefit for all node-negative patients at 15 years, and this SEER subset includes lower-risk patients with shorter follow-up,” she noted.
“While we now have level I data supporting the omission of radiation in selected low-risk, elderly breast cancer patients” she continued, “that does not mean that we should be omitting radiation in all of these patients. The anxiety associated with recurrence varies from patient to patient, and we need to talk with patients individually to determine their goals for treatment. Furthermore, the merits of radiotherapy should be considered on the basis of the data supporting their value, in conjunction with tumor characteristics, comorbities, life expectancy, and patient preferences.” ■
Disclosure:Dr. Moran is on the advisory board of Genomic Health.
