Reduced expression of p16 and p27 is correlated with tumour progression in cutaneous melanoma.
OBJECTIVE
To determine if the cyclin dependent kinase inhibitors (CDKIs) p16 and p27 show reduced expression in the progression from benign to malignant melanocytic tumours, and to correlate these findings with patient prognosis.


METHODS
Ninety-two melanocytic tumours were assessed for immunohistochemical expression of p16 and p27. These specimens included nine compound naevi, 10 dysplastic naevi, 17 thin (<1 mm) melanomas, 22 thick (>1 mm) melanomas, nine in-transit metastases, 13 lymph node metastases, and 12 soft tissue metastases. Clinicopathological information on the 39 patients with melanoma primaries was obtained from the Sydney Melanoma Unit database. The median follow up period was 43.3 months.


RESULTS
A significant loss of expression of p16 and p27 was found with tumour progression. Positive expression of p27 was found in all compound and dysplastic naevi but only 43.6% of melanoma primaries. Expression of p27 was greater in lymph node and in-transit metastases (63.6%), but lower in soft tissue metastases (36.4%). Positive expression of nuclear p16 was evident in 73.7% of benign naevi, 28.2% of primary melanomas and 14.7% of metastatic melanomas. Neither p16 nor p27 expression was significantly correlated with overall survival, disease free survival or other clinicopathological markers.


CONCLUSIONS
The CDKIs p16 and p27 are associated with tumour progression in melanoma, but do not reliably predict recurrence or survival.
Sanki
Amira
A
Sydney Melanoma Unit, Sydney Cancer Centre, Department of Anatomical Pathology, Royal Prince Alfred Hospital, and Discipline of Surgery, University of Sydney, NSW, Australia.
Li
Wei
W
Colman
Marjorie
M
Karim
Rooshdiya Z
RZ
Thompson
John F
JF
Scolyer
Richard A
RA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism*; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008545:Melanoma / Q000378:metabolism* / Q000401:mortality / Q000556:secondary; D008875:Middle Aged; D009367:Neoplasm Staging; D012878:Skin Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D015996:Survival Rate
D014408:Biomarkers, Tumor; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050760:Cyclin-Dependent Kinase Inhibitor p27