Salivary duct carcinoma (SDC) is a highly malignant tumor that is histologically similar to ductal carcinoma of the breast. This article presents the clinicopathologic features of 15 patients with SDC arising in the salivary glands. The majority of patients were male and aged 65 years or older. The tumor was most often located in the parotid gland. Pain, facial palsy, and presence of calcification in the CT scan were diagnostic features suggestive of SDC. Histologically, 27% of the tumors arose from pre-existing pleomorphic adenoma. Perineural and lymphatic invasion were common findings. There was an extensive cervical lymph node involvement (73%). Distant metastasis was the most common cause of failure. Although SDC exhibits an unpredictable clinical course, total parotidectomy with neck dissection and adjunctive radiation therapy appear to be appropriate for local and regional control of this aggressive neoplasm.

Salivary duct carcinoma (SDC) is an uncommon, pathologically distinct entity characterized by its morphologic resemblance to ductal carcinoma of the breast and highly aggressive behavior. Approximately two thirds of patients die within 4 years of initial diagnosis despite aggressive, combined surgical resection and radiotherapy. Review of the literature indicates that androgen receptor (AR), a marker frequently detected in prostatic carcinoma, is expressed in over 90% of SDCs, whereas two common breast carcinoma markers, estrogen and progesterone receptors (ER and PR), are expressed in only 1.3% and 6% of the tumors, respectively, by immunohistochemistry. This hormonal profile suggests that SDC, in contrast to its histiologic similarity to ductal carcinoma of the breast, is immunophenotypically more related to prostatic carcinoma. To substantiate this hypothesis, we performed immunohistochemical staining of 13 cases of SDC for the presence of AR and two prostatic markers, prostate specific antigen (PSA) and prostatic acid phosphatase (PAP). Our results showed multifocal, scattered, moderate immunostaining for PAP and diffuse, moderate immunostaining for PSA in seven (58.3%) and two (16.7%) cases, respectively. These results create a potential diagnostic challenge to surgical pathologists who are dealing with a metastatic adenocarcinoma of AR+/PSA+/-/PAP+/- phenotype, particularly in male patients of unknown primary. Metastatic salivary duct carcinoma should be given serious thought if clinical investigation fails to reveal a prostatic primary. The immunophenotypic homology that exists between SDC and prostatic carcinoma also suggests that antiandrogen therapy as used in the treatment of prostatic carcinoma might be beneficial in patients with metastatic SDC when all other conventional modalities fail.

Purpose: Enhanced prognostication power is becoming more desirable in clinical oncology. In this study, we explored the prognostic potential of multigene hypermethylation profiling in non^small-cell lung cancer. Experimental Design: We evaluated a panel of eight genes (p16, APC, ATM, hMLH1, MGMT, DAPK, ECAD, and RASSF1A) using methylation-specific PCR in 105 archived specimens of non^small-cell lung cancer representing all stages of the illness. We analyzed the effect of gene methylation status on outcome individually in a cumulative manner and in a combinatorial approach using recursive partitioning to identify methylation profiles, which affect overall survival. Results: In this data set, tumors harboring promoter hypermethylation at two or more genes exhibit similar survival trends to others in the cohort. Using recursive partitioning, three genes (APC, ATM, and RASSF1A) emerged as determinants of prognostic groups.This designation retained its statistical significance even when disease stage and age were entered into a multivariate analysis. Using this approach, patients whose tumors were hypermethylated at APC and those hypermethylated at only ATM (not also at APC or RASSF1A) enjoyed substantially longer 1-and 2-year survival than patients in the remaining groups. In 32 adjacent histologically normal lung tissue specimens, we detected similar methylation abnormalities. Conclusion: Assessment of promoter hypermethylation aberrations may facilitate prognostic profiling of lung tumors, but validation in independent data sets is needed to verify these profiles. This system uses material that is abundantly available with linked outcome data and can be used to generate reliable epigenetic determinants.