As there are few data from South Africa, we aimed to determine utility of TTF-1, napsin A, p63 and CK5 immunostaining on fine needle aspiration (FNA) cell block and formalin-fixed paraffin-embedded tissue biopsy specimens in subtyping NSCLC as adenocarcinoma and squamous cell carcinomas.
In order to check the assumption that p63 is a useful marker for squamous cellular differentiation, we used two antibodies: anti-p63 and anti-thyroid transcription factor-1 (TTF-1), based on their immunoexpression to differentiate small cell lung carcinoma (SCLC) from poorly differentiated nonkeratinizing squamous cell carcinoma (SCC).
Furthermore, the serum CKAP4 levels were also higher in patients with stage I adenocarcinoma or squamous cell carcinoma than in healthy controls (P < 0.0001).
D2-40 and P63 expression highlighted both PAC and SCC and seems to be useful in excluding metastatic BrCa with a sensitivity and specificity of 58% and 100%, and 98% and 100%, respectively.
Ber EP4 and MOC 31 immunostains were positive in most cases when performed, and the most specific immunostains for SCC were p63 and p40.Negative mucin stains were helpful.
In the SCCA versus SCC differential diagnosis, p40 and K903 are each marginally more sensitive (92%) than p63 (88%), whereas CK5/6 boasts the greatest specificity (98%). p63's poor specificity (66%) can be improved to 94%, if an H-score ≥150 is used as the cutoff for a positive result.
These results demonstrate that some SCC cell lines are deficient in global nucleotide excision repair and support a role for p63 as a regulator of nucleotide excision repair in SCCs.
Squamous cell carcinomas were confirmed using both histological examination by pathologists and immunohistochemistry analysis with positive staining of P63 and CK5/6 combined with negative CK7 and TTF-1 staining.
The transcription factor p63 belongs to the p53/p63/p73 family and plays key functional roles during normal epithelial development and differentiation and in pathological states such as squamous cell carcinomas.
Finally, analysis of samples from patients with squamous cell carcinoma (SCC), basal cell carcinoma and precursors to invasive SCC demonstrated a significant correlation between p63 and VDR levels when compared with healthy normal skin control samples.
To improve segregation between ADC and SqCC in small samples, the classification of lung cancer was updated in 2011, adding immunohistochemistry (IHC) for p63 and TTF-1 to the diagnostic algorithm.
The identification of the SCC-associated interaction between SOX2 and p63 will enable deeper characterization the downstream targets of this interaction in SCC and normal squamous epithelial physiology.