CD44-positive Cancer Stem-like Cells as a Potential Source of Peritoneal Metastasis After Surgery.

BACKGROUND/AIM: The role of CD44 in gastric cancer-derived peritoneal metastasis is currently unknown. It was previously shown that viable, tumorigenic cancer cells are spilled into the peritoneal cavity during surgery, providing a potential cause of peritoneal recurrence after surgery. The purpose of this study was to elucidate the mechanism of peritoneal metastasis of gastric cancer through the expression of CD44 and to propose a method for preventing peritoneal recurrence. MATERIALS AND METHODS: Gastric cancer cell line MKN-45 was sorted into CD44+ and CD44- cells and then injected intraperitoneally into NOD/ShiJic-scidJcl mice. Differences in tumor-initiating capacity between the two groups were assessed using in vivo limiting dilution assays. Tumors harvested from both groups were examined for CD44 and ALDH1A1 expression using immunohistochemistry. The effects of CD44 blockade with anti-CD44 antibody on cell invasion and peritoneal metastasis formation in vivo were assessed. RESULTS: CD44+ cells showed significantly higher efficiency in initiating peritoneal tumor than CD44- cells. Blockade of CD44 significantly reduced peritoneal dissemination of CD44+ cells in vivo, indicating that the CD44 function of intraperitoneally disseminated cancer cells helped promote the formation of peritoneal metastasis. The margin of established tumors showed clusters of cells co-expressing CD44 and ALDH1A1. Peritoneally administered CD44- cells resulted in peritoneal metastases consisting of CD44+ and CD44- cancer cells. CONCLUSION: CD44 expressing cells are a potential source of peritoneal metastasis after surgery and could be a promising target for preventing peritoneal recurrence.

Progression Potential of Ductal Carcinoma in situ Assessed by Genomic Copy Number Profiling.

BACKGROUND: Ductal carcinoma in situ (DCIS) of the breast is heterogeneous in terms of the risk of progression to invasive ductal carcinoma (IDC). To treat DCIS appropriately for its progression risk, we classified individual DCIS by its profile of genomic changes into 2 groups and correlated them with clinicopathological progression factors. METHODS: We used surgically resected, formalin-fixed, paraffin-embedded tissues of 22 DCIS and 30 IDC lesions. We performed immunohistochemical intrinsic subtyping, array-based comparative genomic hybridization, and unsupervised clustering. RESULTS: The samples were divided into 2 major clusters, A and B. Cluster A showed a greater number of gene and chromosome copy number alterations, a larger IDC/DCIS ratio, a higher frequency of nonluminal subtype, a lower frequency of luminal subtype, and a higher nuclear grade, when compared with cluster B. However, there was no difference in the frequencies of lymph node metastasis between clusters A and B. We identified 9 breast-cancer-related genes, including TP53 and GATA3, that highly contributed to the discrimination of A and B clusters. CONCLUSION: Classification of breast tumors into rapidly progressive cluster A and the other (cluster B) may contribute to select the treatment appropriate for their progression risk.

[Two Cases of Unresectable/Advanced Breast Cancer with Pathological Complete Response after Combination Chemotherapy with Pertuzumab. Trastuzumab, and Docetaxel].

Combination chemotherapy with pertuzumab, trastuzumab, and docetaxel is recommended as the first-line treatment for patients with HER2-positive unresectable or metastatic breast cancer. We report 2 cases of unresectable breast cancer for which pertuzumab, trastuzumab, and docetaxel therapy was effective. Case 1: A woman in her 40s was diagnosed with TxN3aM0, Stage ⅢC, HER2-positive, hormone receptor-positive advanced breast cancer. After administration of 6 courses of pertuzumab, trastuzumab, and docetaxel therapy, she underwent surgery(Bt+Ax[Ⅱ]). Histopathological examination revealed that chemotherapy effect was Grade 3. Case 2: A woman in her 60s was diagnosed with de novo Stage Ⅳ, HER2- positive, hormone receptor-negative breast cancer. She was administered 8 courses of pertuzumab, trastuzumab, and docetaxel therapy as the third-line treatment, because she initially refused treatment. Thereafter, she underwent surgery(Bt+Ax [Ⅰ]). In both cases, histopathological examination revealed complete response after chemotherapy. Thus, combination therapy of pertuzumab and trastuzumab may improve the prognosis in patients with HER2-positive breast cancer.

[A Case of Breast Metastasis of Eccrine Porocarcinoma].

An 80's woman was diagnosed with eccrine porocarcinoma of the head in 2010.T he tumor was removed surgically but relapsed in the cervical and axillary lymph nodes 2 years later.The patient underwent surgery, and received systemic chemotherapy and radiation.Chest CT after treatment revealed an irregular mass and thickened skin in the left breast.Core needle biopsy specimens were used to diagnose metastasis of eccrine porocarcinoma.A wide excision with a 1 cm margin was performed under local anesthesia.After surgery, supraclavicular lymph node recurrence was detected.The patient received palliative care because there was no effective treatment available.Eccrine porocarcinoma is a rare malignant tumor of the intraepidermal sweat duct.Breast metastasis from malignant disease is also rare.To our knowledge, breast metastasis of eccrine porocarcinoma has not been reported.

Immunohistochemical analyses of CD44 variant isoforms in invasive micropapillary carcinoma of the breast: comparison with a concurrent conventional invasive carcinoma of no special type component.

BACKGROUND: Invasive micropapillary carcinoma (IMPC) is a distinct histopathological variant of breast carcinoma and frequently develops lymph node metastases. CD44 is a family of transmembrane glycoprotein receptors with multiple variant isoforms (CD44v), which have tissue-specific expression. Previous studies have demonstrated a loss or gain of CD44v and CD44 standard form (CD44s) expression in breast carcinomas. In this study, we analyzed the immunoprofiles of CD44s, CD44v6, and CD44v9 in IMPC and compared them with those in a concurrent invasive carcinoma of no special type (ICNST) component, thus clarifying the significance of CD44 expression in IMPC. METHODS: Twenty-one consecutive cases of mixed IMPC were included in this study. The expression statuses of CD44s, CD44v6, and CD44v9 in both the IMPC and ICNST components were analyzed semiquantitatively by immunohistochemistry. RESULTS: The immunohistochemical scores of CD44s, CD44v6, and CD44v9 were significantly decreased in the IMPC component compared to the ICNST component (p = 0.00335 for CD44s, p = 0.000982 for CD44v6, and p = 0.00271 for CD44v9). Moreover, the immunohistochemical scores of CD44v6 in the IMPC component and CD44v9 in the ICNST component of lymph node metastasis cases were significantly lower compared to cases without lymph node metastasis (p < 0.01). CONCLUSIONS: Decreased CD44 expression may play an important role in promoting lymph node metastasis in IMPC through an inability or decreased capacity to bind with the surrounding stroma. Moreover, high CD44s+ expression levels in the concurrent ICNST component may be related to the development of IMPC.