The effect of advanced age on the efficacy of radiation therapy for early breast cancer, local prostate cancer and grade III-IV gliomas.

PURPOSE

This study was undertaken to determine the effect of advanced age on radiation therapy outcomes for early breast cancer, local prostate cancer and Grade 3-4 gliomas of the brain.

METHODS AND MATERIALS

Radiation therapy outcomes for three malignancies (N = 1,401) were determined for a geriatric cancer population defined as 70 years of age or older and compared to a non-geriatric cancer population defined as less than 70 years of age. The three patient groups studied were: (a) primary breast cancer patients with clinical Stage I or II disease treated with lumpectomy and radiation therapy (N = 994), (b) local prostate cancer patients with Stage A2, B, or C disease treated with radical radiation therapy (N = 294), and (c) patients with Grade 3-4 gliomas of the brain treated with high dose radiation therapy (N = 113).

RESULTS

For Stage I and II breast cancer, there was no statistically significant difference in the overall 10-year survival rates (63% vs. 73%), 10-year cause-specific disease-free survival rates (70% vs. 63%), and 10-year local breast recurrence free survival rates (76% vs. 79%) comparing the geriatric cancer population to the non-geriatric cancer population. For local prostate cancer, there was no statistically significant difference in the 10-year survival rates (38% vs. 41%) or in the 10-year cause-specific disease-free survival rates (58% vs. 52%) in the geriatric population compared with the non-geriatric population. On the other hand, the use of high dose radiation therapy for malignant gliomas resulted in statistically significant inferior 1-year (18% vs. 38%) and 2-year (0% vs. 10%) survival rates for the geriatric population versus the non-geriatric population.

CONCLUSION

This study strongly supports the use of standard radiation therapy programs for early breast and prostate cancer patients age 70 years or more. However, our study raises questions about the efficacy of radiation therapy in patients over the age of 70 years with Grade 3-4 gliomas.