Early detection of second breast cancers improves survival

NEW YORK (Reuters Health) - In breast cancer survivors, detection of a second breast cancer in the asymptomatic stage can improve survival, according to a report in the March 18th online issue of the Annals of Oncology.

Although other studies have examined this topic, each had certain methodologic limitations, the report indicates.

"To our knowledge, this is the only study to have taken length-time bias into account when quantifying the impact of early, asymptomatic detection of breast cancer," lead author Dr. Nehmat Houssami, from the University of Sydney, Australia, said in a statement issued by the European Society for Medical Oncology.

"This is important," she added, "because slow-growing or indolent cancers have a much smaller probability of proving fatal, and this group of women will tend to be over-represented in the early-detected cancers, biasing the effect of screening to make it appear more beneficial."

The study included 1044 women with a second breast cancer who were seen at a center in Florence, Italy, from 1980 to 2005. Clinical record data linked to a mortality registry were used to gauge the impact of cancer diagnosis timing on survival.

In 699 women, the second cancer was diagnosed in an asymptomatic state, while in the remaining 345 women, symptoms were already apparent (p < 0.0001).

Mammography detected 86 percent of malignancies compared with 57 percent for clinical examination (p < 0.0001). Nonetheless, 13.8 percent of cancers were only detected clinically.

For both ipsilateral cancer recurrences and cancers in the contralateral breast, asymptomatic tumors were smaller than symptomatic ones (p < 0.001). Early-stage tumors were more often found in asymptomatic women.

Detection of second breast cancers in the asymptomatic state, the authors calculate, improved survival by 27 percent to 47 percent.

"I think this work provides a timely reminder of the potential benefit of early detection of second breast cancers and supports ongoing surveillance in this group of women," Dr. Houssami concluded.

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