Immunohistochemistry: a prognostic as well as diagnostic tool?

Proliferative activity and diagnostic delay in oral cancer

BACKGROUND

Tumor stage may relate to the chronology of neoplasm growth and has been used as an outcome variable when studying diagnostic delay in oral cancer. However, tumor growth rate may act as a confounding factor.

METHODS

We reviewed a total of 63 incident cases of oral cancer. The variables considered for the study included age, sex, smoking history, tumor site, TNM stage, Ki-67 score, and diagnostic delay.

RESULTS

Significant differences between survivors and exitus were found in terms of tumor stage at diagnosis (I-II vs III-IV), sex, and Ki-67 scores. When the analysis was adjusted for tumor stage at diagnosis (I-II vs III-IV), proliferative activity resulted to be an independent prognostic factor for survival, whereas diagnostic delay did not influence survival.

CONCLUSION

These results seem to suggest that survival from oral cancer is affected more by the biology of the cancer (rapid tumor growth) than by diagnostic delay.

Incontinentia pigmenti with painful subungual tumors: a two-generation study

We report 2 cases of painful subungual dyskeratotic tumors occurring in a mother and daughter with incontinentia pigmenti (IP) as a late manifestation of the disease. Both patients had a history of similar lesions appearing over a period of years on the digits of both the hands and feet. Biopsy specimens of the current lesions were examined and compared with the previous material available on both patients. The current tumors and the earlier lesions (the latter of which had originally been given diagnoses that included squamous cell carcinoma, keratoacanthoma, and verruca vulgaris) showed similar histopathologic features that were consistent with the late (verrucous) stage of IP. To our knowledge, this is the first reported case of numerous subungual tumors in IP involving more than 1 generation in the same family; the first report of subungual tumors in IP to include a 16-year follow-up; and the first report of a probable recurrence of subungual tumors in IP at the same site of a previously surgically removed tumor.

Analysis of the Ki-67 antigen at the invasive tumour front of human oral squamous cell carcinoma

BACKGROUND

It is hypothesised that cell proliferation, as measured by the Ki-67 labelling index (LI) at the invasive tumour front (ITF) was directly related to the histological grade in human oral squamous cell carcinomas (SCCs).

METHODS

Tissues from 42 human oral SCCs were collected and stained with an antibody directed against the Ki-67 antigen using an advanced polymer staining system. Quantitation of the immunopositive cells was performed on two parallel sections at the invasive tumour front (ITF), using an image analyser. The Ki-67 LI was expressed as the number of positive nuclei/mm2 of epithelium. The control tissue used was normal epithelium at the excision margin.

RESULTS

The mean Ki-67 LI for oral SCCs at the ITF was significantly greater than that for the excision margin tissue (P < 0.0001). There was a positive association between increasing Ki-67 LI and increasing Broders' grade (P < 0.05), with a well-differentiated tumour having the lowest mean Ki-67 LI (1549 +/- 806) and a poorly differentiated tumour having the highest value (2232 +/- 771). A similar trend was observed between the mean Ki-67 LI and Bryne's multifactorial grading system.

CONCLUSIONS

It was concluded from this study that cell proliferation (as measured by the Ki-67 antigen) at the ITF had a strong positive relationship with histological grading in human oral SCC.

Staining of melanocytic neoplasms by melanoma antigen recognized by T cells

We stained benign melanocytic nevi and malignant melanoma with antibodies to melanoma antigen recognized by T cells (Mart-1) to determine if this was useful in differentiating benign from malignant melanocytic neoplasms. Forty-five primary malignant melanomas and 71 benign melanocytic nevi were stained with antibodies to Mart-1. Two cases of malignant melanoma metastatic to lymph node and three cutaneous metastases of malignant melanoma were also stained. The degree of staining was graded into diffuse positive staining, focal positive staining, and negative staining. Thirty-six of 45 primary malignant melanomas stained diffusely positive with antibodies to Mart-1. This included three of five desmoplastic malignant melanomas that showed positive staining. Four melanomas showed faint or focal positive staining. One of two metastases to lymph node showed strong positive staining and one showed no staining. All three cutaneous metastases showed diffuse positive staining. Sixty-one of 71 melanocytic nevi showed no staining or faint staining with antibodies to Mart-1. Ten of 71 melanocytic nevi showed strong positive staining. The majority of these were congenital nevi. Staining with antibodies to Mart-1 antigen was a useful marker of malignant melanoma. However, staining may also be seen in benign melanocytic neoplasms. The presence or absence of staining for Mart-1 antigen cannot be used to differentiate benign melanocytic nevi from malignant melanocytic tumors.