Attaining pathological complete regression for breast conservation - A pilot experience in a developing country

Local recurrence is a formidable risk consideration in employing breast conservation for breast cancer. However pathological complete regression (PCR) from chemotherapy has been associated with improved rates of recurrence. Lower PCR rates have been reported from earlier studies and our approach seeks to obtain higher PCR rates utilizing a two pronged approach of surgery and chemotherapy.

To determine success rates in attaining pathologically complete regression for breast conservation in non-metastatic breast cancer cases in a developing country and their clinical outcome.

Patients diagnosed with early stage breast cancers had sequential anthracycline/taxane based neoadjuvant/adjuvant chemotherapy administered at three weekly intervals. Following an initial excision, re-excisions were done following three courses of doxorubicin based chemotherapy. Subsequent re-excisions in cases with failed complete pathological regression were repeated following additional three doxorubicin based chemotherapy cycles or at sequel third taxane based cycle. Endpoint was pathologically complete regression as determined on permanent sections.

Patients ages ranged between 27 and 67 years, mean age 43years, SD 10.34 years, N = 20 Initial breast tumour sizes ranged between 0.5 and 9 cm, mean 4.05 cm, SD 2.38. There were three T4, four T3 tumours, seven T2 and six T1 tumours. Clinical axillary lymphadenopathy with pathological involvement was present in 11 cases. Histological diagnosis showed 13 cases of invasive ductal carcinoma (65.0%), 2 cases of ductal carcinoma insitu (10.0%), 1 papillary carcinoma (5.0%), 3 cases of invasive lobular carcinoma (15.0%) and non-specific type 1 (5.0%). Immunohistochemistry assessment available in 15 cases was positive for estrogen and progesterone receptors in 10 cases. Two cases (10.0%) exhibited 20% positivity for human epidermal growth factor receptor. Pathological complete regression (PCR) defined as no invasive or insitu tumour residuals in the excised tumour bed, was achieved in the 18 cases assessed. (100%) This was consistent with clinical complete response obtained. It was not determined in 2 cases though clinical complete response was obtained. PCR was determined in ten cases (50.0%) at the first reexcision, second reexcision in 4 cases (20.0%) and third reexcision in 4 cases (20.0%). Mean no of re-excisions 1.67 cm, SD 0.84. Six sequential anthracycline/taxane cycles were administered in 17 cases while three cases received anthracycline based chemotherapy only. Median duration of followup from diagnosis was 48 months ranging between 8 months and 144 months. There were two demises at 48 months and 36 months follow up.

Extended chemotherapy sessions alongside re-excisions were successful in achieving much enhanced rates of pathologically complete remissions at 100% in this yet early report, thus improving breast conservation rates even for T3 and T4 tumours. Our study reports higher PCR rates.