Validation sentinel lymph node biopsy study in cN0 axilla using low-cost dual dye technique: potential solution for resource poor settings.

BACKGROUND: Sentinel lymph node biopsy (SLNB) using radio-pharmaceutical and a blue dye is gold standard for axillary staging in clinically node-negative breast cancer. High costs and limited availability of radio-pharmaceutical and/or gamma probe are major deterrents in performing SLNB in developing countries. In this study, we evaluated feasibility of SLN identification (SLN-IR) of fluorescein-guided (FG) SLNB in combination with methylene blue dye (MBD). METHODS: This was a prospective cross-sectional non-randomized validation study in patients with clinically node-negative axilla. Patients underwent validation SLNB using fluorescein (and blue LED light) and MBD. Axillary dissection was performed irrespective of SLNB histology. SLIN-IR and False Negative Rate (FNR) were assessed for both groups. RESULTS: The SLNs were identified in 29 (96.6%) pre-chemotherapy patients and 23 (82%) post Neoadjuvant Chemotherapy (NACT) patients. The median number of sentinel lymph nodes identified was 3 (range of 1-5) in pre-chemotherapy patients and 1 (range of 1-3) in post NACT patients. The SLN-IR using MBD was 90%, FD was 86.7% and combined MBD FD was 96.7% in pre-chemotherapy patients. The SLN-IR using MBD was 82%, FD was 71% and combined MBD FD was 82% in in post NACT patients. The false negative rate (FNR) in pre-chemotherapy group was 8.0% (MBD), 8.3% (FD) and 7.4% (MBD + FD). The FNR in post NACT group was 8.7% (MBD), 10% (FD) and 8.7% (MBD + FD). CONCLUSION: This prospective validation study showed adequate SLN-IR and FNR using low-cost dual dyes in early breast cancer patients and can be used in low resource settings. However, SLNB in post NACT axilla though viable along with a satisfactory FNR, is associated with low identification rate and needs further evaluation.

Immunohistochemical Detection of p16(INK4a) in Leukoplakia and Oral Squamous Cell Carcinoma.

INTRODUCTION: Over-expression of p16(INK4a) has been reported in tissues of oral squamous cell carcinoma (SCC) associated with Human Papillomaviruses (HPVs). Immunohistochemical (IHC) detection of p16(INK4a) is an easy technique than molecular detection of HPVs, hence we investigated the presence of this protein in the most common pre-malignant and malignant oral lesions i.e. leukoplakia and SCC respectively. MATERIAL AND METHODS: We performed IHC detection of p16(INK4a) in sections of paraffin embedded formalin fixed tissues of leukoplakia with or without dysplasia (n= 21) and SCC lesions (n= 69) and correlated with various patterns of p16(INK4a) positivity with respect to histological diagnosis. RESULTS: In the present study, 71% cases of oral SCC cases were positive for p16(INK4a), of which the most common pattern was diffuse nuclear and cytoplasmic staining. Among the cases with leukoplakia, 57.1% were positive for overexpression of p16(INK4a), wherein diffuse and sporadic pattern was observed among 23.8 percent each. CONCLUSION: In the present study, significant number of oral SCC cases observed overexpressing p16(INK4a) . However HPV DNA detection based studies are needed to validate the utility of IHC detection of p16(INK4a) as a surrogate marker for HPV associated oral SCC.