Breast cancer is the most common newly diagnosed malignancy among American women. In 2008, an estimated 182,460 new cases of invasive breast cancer, and an additional 67,770 cases of in situ cancer were diagnosed. Approximately 40,480 women will die from breast cancer each year.

Up to 10%–15% of patients treated with lumpectomy and whole-breast irradiation (breast-conservation therapy, or BCT) will have a subsequent in-breast local recurrence when followed long term. Salvage mastectomy is widely accepted as the standard of care for local recurrence after BCT.[1-4] Few data in the literature have described the clinical outcome from a second conservative surgery with or without additional radiation therapy among women who do not consent to mastectomy.[5-14]

Prognostic Factors of a Second Cancer Following BCT

Several factors may influence patient outcome after local recurrence following BCT.[15-20] The various prognostic factors include tumor size, histologic subtype of recurrent disease (invasive or noninvasive), involvement of the skin and lymph nodes at the time of recurrence, location of the tumor in the breast in relation to the initially treated breast cancer, and the time interval between the first and second in-breast cancer diagnosis. Patients who have experienced a longer time interval between the two cancers have a better outcome. Kurtz et al[14] reported that when mastectomy was used to treat the recurrence, the 5-year local control rate was 92% for recurrences occurring after 5 years and only 49% for time intervals of less than 5 years.

Further, some investigators have studied clinical and pathologic criteria to help distinguish between a true recurrence and a new primary. Haffty et al[21] distinguished new primaries as lesions that were far removed from the original scar, were of a different histology than the original primary tumor or had diploid tumors in the face of an aneuploid primary tumor. They observed statistically significant differences in the 5-year survival—89% for new primary tumors and 36% for lesions classified as a true recurrence. A subsequent update on this work with a mean follow-up of over 10 years confirmed the differences in outcome between a new primary tumor and a recurrent lesion.[20]

Another study[22] that used clinical and pathologic criteria to differentiate a new primary from a true recurrence observed similar findings. The mean time to the second cancer event was longer for the new primary compared to true recurrence. Both the 10-year overall and distant disease-free survival was significantly better among patients categorized as having new primaries. Of note, the 77% survival rate reported among patients with tumors classified as a new primary is comparable to what we might expect for similar-stage disease at initial presentation. These observations suggest that the prognosis of all second cancer events is not uniformly associated with poor risk. The ability to recognize biologically favorable second events may have implications for the choice of local therapy when individualizing cancer care.

Mastectomy Following Local Recurrence

Salvage mastectomy is the accepted standard of care. Studies on salvage mastectomy have, on average, reported local failure rates of less than 10% with expected control rates of greater than 90%.[23-25]