Breast-conserving therapy ‘avant la lettre’: a long-term follow-up study after radical partial mastectomy and low-dose orthovoltage irradiation for stage I and II breast cancer

From 1954 to 1966, 32 patients with a small, well-outlined breast cancer mostly located in the upper outer quadrant, were treated with a radical partial mastectomy followed by low-dose orthovoltage irradiation. In this series with an almost complete follow-up of median 18.4 years, disease-specific survival was 85% at 5 years and 81% at 10 years. In this small number of patients, no statistically significant prognostic factors for survival could be identified, but data suggest an adverse effect of young age. Thirteen breast recurrences occurred, after an interval of 0.6–29.7 (mean 9.7, median 8.6) years. The actuarial breast recurrence rate at 5 years was 10% (10 years, 33%; 20 years, 47%). The only risk factor for local recurrence identified was an incomplete or doubtfully complete tumourectomy. We believe that the low dose of irradiation contributed to the high breast recurrence rate. In breast-conserving therapy, an adequate radiation dose is important to prevent breast recurrence.