Identification of women with an increased risk of developing radiation-induced breast cancer: a case only study

Introduction

Medroxyprogesterone acetate (MPA) induces estrogen receptor (ER)-positive and progesterone receptor (PR)-positive ductal invasive mammary carcinomas in BALB/c mice. We sought to reproduce this MPA cancer model in C57BL/6 mice because of their widespread use in genetic engineering. Within this experimental setting, we studied the carcinogenic effects of MPA, the morphologic changes in mammary glands that are induced by MPA and progesterone, and the levels of ER and PR expression in MPA-treated and progesterone-treated mammary glands. Finally, we evaluated whether the differences found between BALB/c and C57BL/6 mouse strains were due to intrinsic differences in epithelial cells.

Methods

The carcinogenic effect of MPA was evaluated in C57BL/6 mice using protocols proven to be carcinogenic in BALB/c mice. In addition, BALB/c and C57BL/6 females were treated with progesterone or MPA for 1 or 2 months, and mammary glands were excised for histologic studies and for immunohistochemical and Western blot evaluation of ER and PR. Hormone levels were determined by radioimmunoassay. Isolated mammary epithelial cells were transplanted into cleared fat pads of 21-day-old female Swiss nu/nu mice or control congenic animals.

Results

MPA failed to induce mammary carcinomas or significant morphologic changes in the mammary glands of C57BL/6 mice. The expression of ER-α and PR isoform A in virgin mice was surprisingly much higher in BALB/c than in C57BL/6 mammary glands, and both receptors were downregulated in progestin-treated BALB/c mice (P < 0.05). PR isoform B levels were low in virgin control mice and increased after progestin treatment in both strains. ER-β expression followed a similar trend. No differences in hormone levels were found between strains. Surprisingly, the transplantation of the epithelial mammary gland cells of both strains into the cleared fat pads of Swiss (nu/nu) mice abolished the mammary gland morphologic differences and the ER and PR differences between strains.

Conclusion

C57BL/6 mammary glands are resistant to MPA-induced carcinogenesis and to hormone action. MPA and progesterone have different effects on mammary glands. Low ER-α and PR-A levels in untreated mammary glands may be associated with a low-risk breast cancer profile. Although we cannot at this time rule out the participation of other, untested factors, our findings implicate the stroma as playing a crucial role in the strain-specific differential hormone receptor expression and hormone responsiveness.     

High number of intraepithelial CD8+ tumor-infiltrating lymphocytes is associated with the absence of lymph node metastases in patients with large early-stage cervical cancer

In a prospective study, we have examined the tumor-specific immune response in a group of 59 patients with human papillomavirus (HPV) 16-positive (HPV16(+))-induced or HPV18(+)-induced cervical cancer. Local antitumor immunity was analyzed by the enumeration of tumor-infiltrating dendritic cells and CD4+, CD8+, and regulatory T cells as well as by calculation of the ratio of CD8+/CD4+ T cells and CD8+/regulatory T cells. Systemic tumor-specific immunity was assessed by determination of the HPV E6- and/or E7-specific T-cell response in the blood of these patients. Finally, these variables were evaluated with respect to known histopathologic prognostic variables, including the absence (LN-) or presence (LN+) of lymph node metastases. Stratification according to the lymph node status of patients revealed a significantly stronger CD8+ T-cell tumor infiltration, a higher CD8+/CD4+ T-cell ratio, and higher CD8+/regulatory T-cell ratio in the group of patients in which the tumor failed to metastasize to the tumor-draining lymph node. Subdivision according to the presence (IR+) or absence (IR-) of circulating HPV-specific T cells disclosed that the highest number of tumor-infiltrating CD8+ T cells was found in the group of LN- patients displaying a concomitant systemic tumor-specific immune response (LN-IR+). CD8+ T-cell infiltration in LN-IR- patients was comparable with that of LN+ patients. In cervical cancer, the absence of lymph node metastases is strongly associated with a better prognosis. Our data indicate that, especially in a subgroup of LN- patients, a strong and effective interaction between immune system and tumor exists. This subgroup of cervical cancer patients may have the best prognosis.     

Cysts within and adjacent to the lesser tuberosity: correlation with shoulder arthroscopy

Objective

The purpose of our study was to determine if cysts in and adjacent to the lesser tuberosity are associated with rotator cuff pathology found at arthroscopy.

Materials and methods

A retrospective review was undertaken of the magnetic resonance (MR) imaging of 286 consecutive arthroscopic procedures performed by a single orthopedic shoulder surgeon from February 2001 to June 2009. Images of the shoulders were reviewed by an experienced fellowship-trained musculoskeletal radiologist, reader 1, and a musculoskeletal fellow, reader 2, for the presence and location of lesser tuberosity cysts. Cysts were grouped by their location into those within the lesser tuberosity and those adjacent to the lesser tuberosity. Interreader agreement was calculated using kappa values.

Results

A total of 26 patients (17 men, 9 women; age range 14–84?years; mean of 61?years) had cysts in or adjacent to the lesser tuberosity. For reader 1, patients with cysts located in the lesser tuberosity were found to be significantly older (p?=?0.03) and more likely to have subscapularis tendon tears (p?=?0.02) than patients with cysts located adjacent to the tuberosity. No significant difference in any category between patients with a cyst located in the lesser tuberosity and those adjacent to the tuberosity was identified for reader 2. Interreader agreement of imaging findings ranged from fair to near perfect agreement.

Conclusion

Cysts located in the lesser tuberosity at the insertion of the subscapularis tendon are suggestive of subscapularis tendon pathology and may occur in older individuals.     

Increased day 15-17 serum pro-alphaC inhibin levels specific to successful pregnancy

In early pregnancy, serum levels of the luteal-derived hormone pro-alphaC inhibin peak by the second week after conception. Whether this early rise is biologically important and a consistent feature of only successful pregnancy is unknown. We undertook a prospective cross-sectional study to determine whether serum pro-alphaC inhibin levels at d 15-17 are predictive of a successful clinical in vitro fertilization pregnancy and compared levels between fresh embryo transfer (ET) and frozen-thawed ET. Median (95% confidence interval) pro-alphaC inhibin levels were 68 (57-76) pg/ml in 204 women who did not become clinically pregnant after ET, significantly lower than in either 90 women who became clinically pregnant after fresh ET and who had 3139 (1684-4220) pg/ml or in 39 women with a successful frozen ET who had 877 (678-1111) pg/ml. Pro-alphaC was highly sensitive and specific in predicting clinical pregnancy success but did not improve on the performance of human chorionic gonadotropin. Pro-alphaC inhibin levels were not correlated with progesterone or human chorionic gonadotropin. Levels were no higher in singleton compared with multiple pregnancies and did not increase across gestation, suggestive of a luteal source. The increase in circulating pro-alphaC inhibin in very early pregnancy is highly specific to clinical pregnancy, suggesting a possible biological role in early gestation.     

EMMPRIN-induced MMP-2 activation cascade in human cervical squamous cell carcinoma

Tumor progression and recurrence of cervical cancer is associated with upregulation of matrix metalloproteinase 2 (MMP-2). We evaluated the location, origin and activity of MMP-2 in cervical squamous cell carcinomas in comparison with MT1-MMP (MMP-14), TIMP-2 and extracellular matrix metalloproteinase inducer (EMMPRIN). Positive immunostaining for MMP-2 in malignant cells was detected in 83% of the patients. Two patterns of tumor cell MMP-2 staining were observed: either homogenous in all tumor cells or confined to the cells neighboring the stroma (tumor-border staining pattern, TBS). Fluorescence in situ zymography showed active MMP-2 mainly around tumor nodules displaying TBS. The MMP-2 staining of TBS tumors correlated significantly with the presence of TIMP-2 and MT1-MMP, proteins involved in docking MMP-2 to the cell surface and essential for MMP-2 activation. In situ mRNA hybridization in TBS tumors demonstrated more abundant presence of MMP-2 mRNA in neighboring myofibroblasts than in the adjacent tumor cells. Moreover, the TBS MMP-2 pattern correlated with the presence of EMMPRIN (p = 0.023), suggesting that tumor cells induce MMP-2 production in nearby stromal cells. This pro-MMP-2 could subsequently be activated on tumor cells via the presence of MT1-MMP and TIMP-2. The biological relevance of this locally activated MMP-2 was underscored by the observation that only the TBS pattern of MMP-2 significantly correlated with decreased survival. In conclusion, the colocalization of EMMPRIN, MT1-MMP and TIMP-2 in human cervical carcinomas seems to be involved in a specific distribution pattern of tumor cell bound MMP-2, which is related with local proteolytic activity and therefore might be associated with worse prognosis of the patients.     

Rapid enrichment of human papillomavirus (HPV)-specific polyclonal T cell populations for adoptive immunotherapy of cervical cancer

The majority of cervical cancers are caused by human papillomavirus type 16 (HPV16). Cervical cancer is associated with an ineffective host immune response against the HPV16 oncoproteins, characterized by the lack of the strong E6-specific T-helper type 1 (Th1) immunity that is generally present in healthy individuals, the presence of improperly polarized HPV16E6- and E7-specific CD4(+) T cells and increased numbers of regulatory T cells. Therefore, immunotherapeutic intervention is likely to require a modality that deletes the regulatory T cell component and enhances the HPV16-specific Type 1 T cell response. HLA-matched allogeneic stem cell transplantation may offer such a modality, because it involves the eradication of host immune cells and enables the transfer of donor derived tumor-specific T cells to the patient. As a first step in the development of such a treatment, we evaluated the success rate of a protocol for enrichment of HPV16E6-specific CD4(+) T cells from healthy donor PBMC on the basis of their IFNgamma secretion. After a short in vitro stimulation with overlapping 30 amino acid long HPV16E6 peptides, we enriched the IFNgamma secreting cells by magnetic cell sorting. The obtained polyclonal CD4(+) T cell populations recognized distinct epitopes within HPV16E6, as well as E6 protein, processed and presented by autologous professional antigen presenting cells. The described protocol proved successful in PBMC from more than half of the healthy adult blood donors. These HPV16E6-specific CD4(+) T cells may turn out to be an essential component of future adoptive T cell therapy for advanced cervical cancer, by orchestrating CTL dependent and independent tumoricidal mechanisms.