BACKGROUNDDue to the low incidence of salivary duct carcinoma (SDC), only limited data in regard to the biologic behavior of this tumor and its immunohistochemical characteristics are available. The authors analyzed the clinical, molecular, and genetic profile of SDC and identified prognostic factors.METHODSThe follow‐up of 50 patients with SDC was obtained and paraffin‐embedded tumor samples were examined immunohistochemically. In all samples, the expression of Ki‐67, HER‐2, and the oncoproteins p16 and p53 was examined immunohistochemically, followed by a mutation analysis of p16 and p53. The survival rate was calculated by the Kaplan–Meier method and prognostic variables were analyzed with the log‐rank test.RESULTSSDC predominantly effected male patients (66%) in their 7th decade of life. SDC mainly occurred in the parotid gland (78%; submandibular gland, 12%; minor salivary glands, 10%). Approximately two‐thirds of the patients (33 of 50) presented with a T3/T4 tumor. In 28 patients (56%), cervical lymph node metastasis was present at the time of diagnosis. Local disease recurrence was observed in 48% of patients an average of 17.4 months after initial treatment. Distant disease metastasis developed in 48% of patients an average of 29 months after initial treatment. The average overall survival period was 56.2 months. In the current study, 20.6% of the probes with positive HER‐2/neu expression were (+++) positive. p53 was expressed in 83.9% of the tumor samples. In 11.8% of the tumor samples, there was a lack of p16 expression.CONCLUSIONSMutations of the p53 gene were more frequent in tumor samples with (++) and (+++) immunoreactivity and mainly affected exons 7 and 8. A mutation of the p16 gene was only found in 1 tumor sample. Expression of HER‐2/neu and p53 was statistically linked (P < 0.05) to early local disease recurrence, distant disease metastasis, and survival rates. Cancer 2005. © 2005 American Cancer Society.

Recent studies have shown that the recurrent t(6;9)(q22-23;p23-24) translocation in adenoid cystic carcinoma results in a novel fusion of the MYB proto-oncogene with the transcription factor gene NFIB. To determine the frequency of this finding, we used RT-PCR assays of the MYB and MYB-NFIB fusion transcripts, and immunohistochemistry for the MYB protein, to study adenoid cystic carcinomas and other epithelial tumors of the salivary glands, and head and neck region. MYB-NFIB fusion transcript was detected in 25 of 29 (86%) frozen adenoid cystic carcinoma tumor samples, and in 14 of 32 (44%) formalin-fixed paraffin-embedded adenoid cystic carcinoma tumor specimens. In contrast, the MYB-NFIB fusion was not expressed in non-adenoid cystic carcinoma neoplasms of the head and neck, confirming the high specificity of the MYB-NFIB fusion. Adenoid cystic carcinomas from various anatomic sites, including salivary gland, sinonasal cavity, tracheobronchial tree, larynx, breast, and vulva were repeatedly fusion-positive, indicating that adenoid cystic carcinomas located in different anatomic sites not only have important morphologic features in common, but also probably evolve through activation of the same molecular pathways. Studies of the expression of MYB revealed that 89% of the tumors, including both fusion-positive and fusion-negative cases, overexpressed MYB RNA. Similarly, 82% of adenoid cystic carcinomas stained positive for MYB protein, compared with 14% of non-adenoid cystic carcinoma neoplasms, indicating that MYB immunostaining may be useful for the diagnosis of adenoid cystic carcinoma, but that neoplasms sometimes in the differential diagnosis are also labeled. The latter are, however, fusion-negative. In summary, our studies show that MYB activation through gene fusion or other mechanisms is a major oncogenic event in adenoid cystic carcinoma occurring at various anatomic sites. In addition to being a diagnostically useful biomarker for adenoid cystic carcinoma, MYB and its downstream effectors are also novel potential therapeutic targets.

Recurrent chromosomal alterations are found in roughly 20% of all uterine fibroids but in the majority cytogenetic changes are lacking. Recently, mutations of the gene mediator subcomplex 12 (MED12) have been detected in a majority of fibroids but no information is available whether or not they co-occur with cytogenetic subtypes as, e.g., rearrangements of the genes encoding high mobility group AT-hook (HMGA) proteins. In a total of 80 cytogenetically characterized fibroids from 50 patients, we were not only able to confirm the frequent occurrence of MED12 mutations but also to stratify two mutually exclusive pathways of leiomyomagenesis with either rearrangements of HMGA2 reflected by clonal chromosome abnormalities affecting 12q14~15 or by mutations affecting exon 2 of MED12. On average the latter mutations were associated with a significantly smaller tumor size. However, G>A transitions of nucleotides c.130 or c.131 correlate with a significantly larger size of the fibroids compared to other MED12 mutations thus explaining the high prevalence of the former mutations among clinically detectable fibroids. Interestingly, fibroids with MED12 mutations expressed significantly higher levels of the gene encoding wingless-type MMTV integration site family, member 4 (WNT4). Based on these findings and data from the literature, we hypothesize that estrogen and the mutated MED12 cooperate in activating the Wnt pathway which in turn activates b-catenin known to cause leiomyoma-like lesions in a mouse model. The occurrence of a ''fibroid-type mutation'' in a rare histologic subtype of endometrial polyps suggests that this mechanism is not confined to uterine leiomyomas.Uterine leiomyomas (syn.: fibroids) are among the most frequent clinically relevant human tumors leading, e.g., to abdominal pain, bleeding and infertility. Their prevalence clearly differs depending on ethnicity but in most countries exceeds 50% of all women in their reproductive ages.

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Breast cancers demonstrate substantial biological, clinical and etiological heterogeneity. We investigated breast cancer risk associations of eight susceptibility loci identified in GWAS and two putative susceptibility loci in candidate genes in relation to specific breast tumor subtypes. Subtypes were defined by five markers (ER, PR, HER2, CK5/6, EGFR) and other pathological and clinical features. Analyses included up to 30 040 invasive breast cancer cases and 53 692 controls from 31 studies within the Breast Cancer Association Consortium. We confirmed previous reports of stronger associations with ER+ than ER- tumors for six of the eight loci identified in GWAS: rs2981582 (10q26) (P-heterogeneity = 6.1 × 10(-18)), rs3803662 (16q12) (P = 3.7 × 10(-5)), rs13281615 (8q24) (P = 0.002), rs13387042 (2q35) (P = 0.006), rs4973768 (3p24) (P = 0.003) and rs6504950 (17q23) (P = 0.002). The two candidate loci, CASP8 (rs1045485, rs17468277) and TGFB1 (rs1982073), were most strongly related with the risk of PR negative tumors (P = 5.1 × 10(-6) and P = 4.1 × 10(-4), respectively), as previously suggested. Four of the eight loci identified in GWAS were associated with triple negative tumors (P ≤ 0.016): rs3803662 (16q12), rs889312 (5q11), rs3817198 (11p15) and rs13387042 (2q35); however, only two of them (16q12 and 2q35) were associated with tumors with the core basal phenotype (P ≤ 0.002). These analyses are consistent with different biological origins of breast cancers, and indicate that tumor stratification might help in the identification and characterization of novel risk factors for breast cancer subtypes. This may eventually result in further improvements in prevention, early detection and treatment.