December 2012, Vol 1, No 6

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Two Studies Show That Radiation Extends Survival in Elderly Women With Early-Stage Breast Cancer

Phoebe Starr


Radiation therapy extends life in older women with early-stage breast cancer, according to 2 studies presented at the 54th Annual Meeting of ASTRO.

The first study showed that the addition of radiation to lumpectomy improved overall survival (OS) as well as cause-specific survival (CSS) in women aged 70 or older.

The study population included 29,949 women identified in a SEER Medicare database who were diagnosed with stage I, estrogen receptor–positive (ER+) breast cancer. All women underwent lumpectomy with or without adjuvant radiation and survived at least 1 year after the initial diagnosis. Seventy-six percent received adjuvant radiation therapy.

Median survival was 13.1 years for women treated with surgery plus radiation and 11.1 years for those treated with surgery alone. Five-year CSS was 98.3% for the adjuvant radiation group versus 97.6% for the surgery-alone group. Ten-year CSS was 95.4% versus 93.3%, respectively; 15-year CSS was 91.4% versus 89.5%, respectively.

At all time points, the use of adjuvant radiation improved OS. At 5 years, OS was 88.6% for those who received radiation versus 73.1% for the surgery-alone arm (P<.0001); at 10 years, OS was 65% versus 41.7%, respectively (P<.0001); at 15 years, OS was 39.6% versus 20%, respectively.

A related study based on 27,559 patients from a SEER Medicare database found that older women with early-stage, low-risk breast cancer treated with radiation after breast-conserving surgery (BCS) had superior CSS and OS rates compared with women who did not undergo radiation after BCS. The study showed a 6% decline in use of radiation after 2004, coinciding with revised National Comprehensive Cancer Network guidelines allowing omission of radiation therapy as a reasonable option for women over age 70 with small ER+ tumors treated with adjuvant tamoxifen.

CSS favored radiotherapy. At 5 years, CSS was 97% for those who received radiotherapy versus 95% for those who did not, an absolute difference of 2%; by 10 years, the absolute difference was doubled to 4%, favoring radiation: 95% and 91%, respectively.

OS also favored the addition of radiotherapy to surgery. Five-year OS was 87% versus 68%, respectively, with an absolute difference of 19% favoring radiation, and 8-year OS was 73% versus 50%, respectively, for an absolute difference of 23% favoring radiation.

Interview with the Innovators - December 20, 2012

Lynch Syndrome:

An Interview with the Father of Hereditary Cancer Detection and Prevention, Henry T. Lynch, MD

Lynch syndrome is a hereditary disorder caused by a mutation in a mismatch repair gene in which affected individuals have an increased risk of developing colorectal cancer, endometrial cancer, and various other types of aggressive cancers. The syndrome is named after its discoverer, Henry T. Lynch, MD, director of Creighton [ Read More ]

Colorectal Cancer - December 20, 2012

KRAS and Colorectal Cancer: Shades of Gray

Key Points Although RAS mutations at glycine-12 and glycine-13 are adjacent, identical substitutions at these positions (eg, G12S vs G13S) lead to very different levels of RAS activation The central clinical question remains unanswered: will a patient with metastatic colorectal cancer harboring a KRAS G13D mutation benefit from anti-EGFR therapy? [ Read More ]