EARLY SURGICAL OUTCOMES OF OPERABLE BREAST CANCER PATIENTS BASED ON MOLECULAR SUBTYPING – A SINGLE-CENTRE STUDY

Abstract

Objectives: The aim of the study was to assess patients belonging to four main molecular subtypes (Luminal A, Luminal B, HER2 neu positive and Triple negative) and their treatment plans with a view to compare their early surgical complications and the final outcomes specific to the surgical procedure adopted and molecular subtype.

Methods: A Cross-sectional observational study at a Tertiary care center in central UP in a two-year period with Inclusion Criteria and Exclusion Criteria. Data Collection was carried out from the patients, diagnostic confirmation to rule out any exclusion criteria was performed. Clinical staging was done using the standard TNM criteria. All the specimens were subjected to immune-histochemical evaluation for surrogate molecular subtyping to see later the early surgical outcomes.

Results: Mean age ranged from 47.57±9.57 (Group III) to 50.67±8.08 (Group II) years and BMI ranged from 23.71 (Group IV) to 26.38 kg/m2 (Group II). Neoadjuvant chemotherapy use was reported in 15.6% of Luminal A group, 33.3% of Luminal B group, 40% of Her2 negative and 52.2% of Triple negative group cases. Statistically, there was a significant difference among groups with respect to use of neoadjuvant chemotherapy. Breast conservation therapy was the preferred surgical intervention in majority of cases with Luminal A (60%) and Luminal B subtype (66.7%) whereas MRM was preferred in 54.3% of Her2 negative and 65.2% of Triple negative cases. MRM was performed in 36% of Luminal A cases. Primary surgical intervention failure (BCS) was seen in 1 (4%) case with Luminal A subtype. In this patient, mastectomy was performed as the corrective measure. Surgical site infection was noted in 1 (4%) case in Luminal A group only. Seroma formation was noted in 4 (16%) of Luminal A, 8 (22.9%) of Her2 negative and 2 (8.7%) of Triple negative patients. No case of flap necrosis was noted. Follow-up duration ranged from 15 days to 36 months. Median duration of follow-up was 6 months. No mortality was noticed in any group.

Conclusion: Different surgical management strategies suggested that breast conservative surgery was more feasible in Luminal A cases whereas MRM was the preferred mode of surgery in other molecular subtypes. Within the limitations of short duration of follow-up, there was no significant difference among different molecular subtypes with respect to late complications and survival. Further studies with longer duration of follow-up and larger sample size are recommended.