Is postmastectomy radiotherapy necessary for breast cancer patients with clinically node-positive downstaging to ypN0 after neoadjuvant chemotherapy?

PURPOSE

The significance of postmastectomy radiotherapy (PMRT) in breast cancer patients who initially have clinically node-positive (cN +) status but achieve downstaging to ypN0 following neoadjuvant chemotherapy (NAC) remains uncertain. This study aims to assess the impact of PMRT in this patient subset.

METHODS

Patients were enrolled from West China Hospital, Sichuan University from 2008 to 2019. Overall survival (OS), Locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and breast cancer-specific survival (BCSS) were estimated using the Kaplan-Meier method and assessed with the log-rank test. The impact of PMRT was further analyzed by the Cox proportional hazards model. Propensity score matching (PSM) was performed to reduce the selection bias.

RESULTS

Of the 333 eligible patients, 189 (56.8%) received PMRT, and 144 (43.2%) did not. At a median follow-up period of 71 months, the five-year LRFS, DMFS, BCSS, and OS rates were 99.1%, 93.4%, 96.4%, and 94.3% for the entire cohort, respectively. Additionally, the 5-year LRFS, DMFS, BCSS, and OS rates were 98.9%, 93.8%, 96.7%, and 94.5% with PMRT and 99.2%, 91.3%, 94.9%, and 92.0% without PMRT, respectively (all p-values not statistically significant). After multivariate analysis, PMRT was not a significant risk factor for any of the endpoints. When further stratified by stage, PMRT did not show any survival benefit for patients with stage II-III diseases.

CONCLUSION

In the context of comprehensive treatments, PMRT might be exempted in ypN0 breast cancer patients. Further large-scale, randomized controlled studies are required to investigate the significance of PMRT in this patient subset.

The Effect of Postmastectomy Radiotherapy on Breast Cancer Patients After Neoadjuvant Chemotherapy by Molecular Subtype

BACKGROUND

The effect of postmastectomy radiotherapy (PMRT) on patient outcomes after neoadjuvant chemotherapy (NAC) remains controversial. We aimed to establish a model to identify the subsets benefiting from PMRT and to examine the effect of PMRT according to molecular subtype.

PATIENTS AND METHODS

We retrospectively analyzed 1118 cT1-4cN0-3M0 breast cancer patients treated with NAC and mastectomy. A nomogram predicting locoregional recurrence (LRR) was established based on 418 unirradiated patients, and X-tile analysis was performed to divide the patients into two risk groups. The effect of PMRT on LRR, distant recurrence (DR), and breast cancer mortality (BCM) was estimated for patients with different molecular subtypes in two risk groups.

RESULTS

A nomogram predicting LRR was developed using six factors: histologic classification, lymphovascular invasion, ypT stage, ypN stage, estrogen receptor status, and Ki-67 expression. Our study found that PMRT correlated with lower 5-year LRR, DR, and BCM rates for the high-risk group; however, no significant improvement in these endpoints was observed in the low-risk group. Among patients with high risk, subgroup analysis showed that LRR control was improved after PMRT for the human epidermal growth factor receptor 2 (HER2)-negative/hormone receptor (HR)-positive (HER2-/HR+), HER2-positive (HER2+)/HR+, and HER2-/HR-negative (HR-) subtypes, with hazard ratios of 0.113 (95% confidence [CI] 0.034-0.379; p < 0.001), 0.159 (95% CI 0.038-0.671; p = 0.017), and 0.243 (95% CI 0.088-0.676; p = 0.007), respectively, but not for the HER2+/HR- subtype (p = 0.468).

CONCLUSIONS

We built a nomogram showing favorable risk quantification and patient stratification. Patients in the high-risk group benefited from PMRT, but patients in the low-risk group did not. PMRT may show different benefits for each molecular subtype.

Public health insurance and cancer-specific mortality risk among patients with breast cancer: A prospective cohort study in China

Little is known about how health insurance policies, particularly in developing countries, influence breast cancer prognosis. Here, we examined the association between individual health insurance and breast cancer-specific mortality in China. We included 7436 women diagnosed with invasive breast cancer between 2009 and 2016, at West China Hospital, Sichuan University. The health insurance plan of patient was classified as either urban or rural schemes and was also categorized as reimbursement rate (ie, the covered/total charge) below or above the median. Breast cancer-specific mortality was the primary outcome. Using Cox proportional hazards models, we calculated hazard ratios (HRs) for cancer-specific mortality, contrasting rates among patients with a rural insurance scheme or low reimbursement rate to that of those with an urban insurance scheme or high reimbursement rate, respectively. During a median follow-up of 3.1 years, we identified 326 deaths due to breast cancer. Compared to patients covered by urban insurance schemes, patients covered by rural insurance schemes had a 29% increased cancer-specific mortality (95% CI 0%-65%) after adjusting for demographics, tumor characteristics and treatment modes. Reimbursement rate below the median was associated with a 42% increased rate of cancer-specific mortality (95% CI 11%-82%). Every 10% increase in the reimbursement rate is associated with a 7% (95% CI 2%-12%) reduction in cancer-specific mortality risk, particularly in patients covered by rural insurance schemes (26%, 95% CI 9%-39%). Our findings suggest that underinsured patients face a higher risk of breast cancer-specific mortality in developing countries.

MiR-4653-3p and its target gene FRS2 are prognostic biomarkers for hormone receptor positive breast cancer patients receiving tamoxifen as adjuvant endocrine therapy

Long-term tamoxifen treatment significantly improves the survival of hormone receptor-positive (HR+) breast cancer (BC) patients. However, tamoxifen resistance remains a challenge. We aimed to identify prognostic biomarkers for tamoxifen resistance and reveal the underlying mechanism. From March 2001 to September 2013, 400 HR+ BC women (stage I~III) were treated with adjuvant tamoxifen for 5 years or until relapse in West China Hospital. We included a discovery set of 6 patients who were refractory to tamoxifen, and a validation cohort of 88 patients including 35 cases with relapse. In the discovery set, microRNA microarray showed that miR-4653-3p decreased in recurrent/metastatic lesions compared to the matched primary lesions. In the validation cohort, real-time RT-PCR demonstrated that, following tamoxifen treatment, miR-4653-3p overexpression in the primary tumors decreased the risk of relapse (adjusted hazard ratio [HR] = 0.17, 95% confidence interval [CI] = 0.05~0.57, P = 0.004). Conversely, high expression of FRS2, the key adaptor protein required by FGFR signaling, predicted poor disease-free survival (DFS) (adjusted HR = 2.70, 95% CI = 1.11~6.56, P = 0.03). MiR-4653-3p down regulated FRS2 by binding to its 3′ untranslated region. Either overexpressing miR-4653-3p or attenuating FRS2 expression could restore TAM sensitivity in two tamoxifen-resistant BC cell lines. In conclusion, high miR-4653-3p level was the potential predictor for favorable DFS, while FRS2 overexpression was potential high-risk factor for relapse in HR+ BC patients receiving TAM adjuvant therapy. FGFR/FRS2 signaling might be a promising target for reversing tamoxifen resistance.

Changes in Body Mass Index, Leptin, and Leptin Receptor Polymorphisms and Breast Cancer Risk

Obesity is a strong risk factor for breast cancer. The polymorphisms of leptin (LEP) and leptin receptor (LEPR) may be associated with breast cancer by regulator of adipose tissue mass and tumor cell growth. A total of 794 cases and 805 matched controls were sequentially enrolled. Time-of-flight mass spectrometry was used to determine the LEPrs7799039, LEPRrs1137100, and LEPRrs1137101 genotypes for each participant. Associations between polymorphisms of these genes, change in body mass index (BMI), and breast cancer risk were assessed by unconditional multivariable logistic regression models. The unconditional logistic regression model showed that persistent overweight (BMI ≥24 kg/m²) over the preceding 10 years was associated with increased breast cancer risk in premenopausal women (odds ratio [OR] = 1.67, 95% confidence interval [CI]: 1.19-2.35). No associations between LEPrs7799039, LEPRrs1137100, or LEPRrs1137101 polymorphisms alone and breast cancer risk were found. Persistent overweight over the preceding 10 years and carrying the LEPrs7799039 AA genotype together increased breast cancer risk in premenopausal women (OR_adj = 2.00, 95% CI: 1.26-3.16). Persistent overweight over the preceding 10 years and carrying the LEPRrs1137100 GG genotype increased breast cancer risk in premenopausal women (OR_adj = 1.68, 95% CI: 1.06-2.68). In premenopausal women, persistent overweight (BMI ≥24 kg/m²) over the preceding 10 years increases breast cancer risk. Persistent overweight along with LEPrs7799039 AA or LEPRrs1137100 GG genotypes synergistically increase risk of breast cancer among premenopausal women.

CD55 and CD59 expression protects HER2-overexpressing breast cancer cells from trastuzumab-induced complement-dependent cytotoxicity

A large proportion (40-60%) of patients with human epidermal growth factor receptor 2 (HER2)-overexpressing breast cancer do not benefit from trastuzumab treatment, potentially due to the lack of complement-dependent cytotoxicity (CDC) activation. In the present study, the effect of complement decay-accelerating factor (CD55) and CD59 glycoprotein precursor (CD59) expression on trastuzumab-induced CDC in HER2-positive breast cancer cell lines was investigated. The CD55 and CD59-overexpressing and HER2-positive cell lines SK-BR-3 and BT474 were selected for subsequent experiments. Blocking CD55 and CD59 function using targeting monoclonal antibodies significantly enhanced the cell lysis of SK-BR-3 and BT474 cells following treatment with trastuzumab. In addition, following treatment with 0.1 U/ml phosphatidylinositol-specific phospholipase C (PI-PLC) for 1 h, CD55 and CD59 surface expression was significantly decreased, and the cell lysis rate was further enhanced. Treatment of SK-BR-3 cells with short hairpin RNA (shRNA) targeting CD55 and CD59 downregulated CD55 and CD59 expression at the mRNA and protein levels, and resulted in significantly enhanced trastuzumab-induced CDC-dependent lysis. The data from the present study suggested that CD55 and CD59 serve roles in blocking trastuzumab-induced CDC, therefore strategies targeting CD55 and CD59 may overcome breast cancer cell resistance to trastuzumab. The results from the present study may provide a basis for developing suitable, personalized treatment strategies to improve the clinical efficacy of trastuzumab for patients with HER2-positive breast cancer.

[Survival of Patients with Metastatic Recurrent Triple-negative Breast Cancer]

OBJECTIVES

To determine factors associated with the survival of patients with metastatic recurrent triple-negative breast cancer (mrTNBC).

METHODS

Initial metastatic recurrent (during or after therapy) patients with triple-negative breast cancer (TNBC) confirmed by post-operate pathology in the West China Hospital of Sichuan University were followed up. The accumulative survival rates after recurrence were calculated using Kaplan-Meier method and differences were tested using log-rank tests. Cox proportional hazards regression analyses were performed to identify independent predictors of survival rates.

RESULTS

A total of 142 patients were included in this study. They were followed up on average 41.9 months (range: 5.1-189.5 months), and had median post-recurrence survival time of 22.0 months.Tumor diameter, lymph node status, TNM stage, disease-free interval (DFI), numbers of recurrent lesions, brain metastasis, liver metastasis and the rapeutic patterns were associated with the survival of patients. The Cox proportional hazards regression model identified multi-lesions recurrence ( P=0.004), DFI≤12 months ( P=0.010), brain metastasis ( P=0.037) and single-modal therapy (SMT) ( P<0.001) as independent risk predictors of post-recurrence survival. In the patients with local recurrence, multi-modal therapy (MMT) had 53.0%post-recurrence 3-year survival rate compared with 11.4% of SMT ( P=0.024). Similar results were also found in the patients with distant metastases (post-recurrence 3-year survival rate 58.1% for MMT versus 29.3% for SMT, P=0.003).

CONCLUSIONS

Multi-lesions recurrence, short DFI and brain metastasis are independent risk predictors, while MMT is a protective factor for the survival of patients with mrTNBC.

Novel link between prostaglandin E2 (PGE2) and cholinergic signaling in lung cancer: The role of c-Jun in PGE2-induced α7 nicotinic acetylcholine receptor expression and tumor cell proliferation

BACKGROUND

Cyclooxygenase-2-derived prostaglandin E2 (PGE2) stimulates tumor cell growth and progression. α7 nicotinic acetylcholine receptor (nAChR) is a major mediator of cholinergic signaling in tumor cells. In the present study, we investigated the mechanisms by which PGE2 increases non-small cell lung cancer (NSCLC) proliferation via α7 nAChR induction.

METHODS

The effects of PGE2 on α7 nAChR expression, promoter activity, and cell signaling pathways were detected by Western blot analysis, real time reverse transcriptase polymerase chain reaction, and transient transfection assay. The effect of PGE2 on cell growth was determined by cell viability assay.

RESULTS

We found that PGE2 induced α7 nAChR expression and its promoter activity in NSCLC cells. The stimulatory role of PGE2 on cell proliferation was attenuated by α7 nAChR small interfering ribonucleic acids (siRNA) or acetylcholinesterase. PGE2-induced α7 nAChR expression was blocked by an antagonist of the PGE2 receptor subtype EP4 and by EP4 siRNA. Furthermore, PGE2 enhanced α7 nAChR expression via activation of c-Jun N-terminal kinase (JNK), phosphatidylinositol 3-kinase (PI3-K), and protein kinase A (PKA) pathways followed by increased c-Jun expression, a critical transcription factor. Blockade of c-Jun diminished the effects of PGE2 on α7 nAChR promoter activity and protein expression, and cell growth.

CONCLUSION

Our results demonstrate that PGE2 promotes NSCLC cell growth through increased α7 nAChR expression. This effect is dependent on EP4-mediated activation of JNK, PI3K, and PKA signals that induce c-Jun protein expression and α7 nAChR gene promoter activity. Our findings unveil a novel link between prostanoids and cholinergic signaling.

Vascular endothelial growth factor (VEGF) gene polymorphisms and breast cancer risk in a Chinese population

Vascular endothelial growth factor (VEGF) is a potent regulator of angiogenesis and thereby involved in the development and progression of solid tumours. Associations between three VEGF gene polymorphisms (-634 G/C, +936 C/T, and +1612 G/A) and breast cancer risk have been extensively studied, but the currently available results are inconclusive. Our aim was to investigate associations between three VEGF gene polymorphisms and breast cancer risk in Chinese Han patients. We performed a hospital-based case-control study including 680 female incident breast cancer patients and 680 female age-matched healthy control subjects. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis was performed to detect the three VEGF gene polymorphisms. We observed that women carriers of +936 TT genotypes [odds ratio (OR) =0.46, 95% confidence interval (CI) = 0.28, 0.76; P=0.002] or 936 T-allele (OR=0.81, 95% CI= 0.68, 0.98; P=0.03) had a protective effect concerning the disease. Our study suggested that the +1612G/A polymorphism was unlikely to be associated with breast cancer risk. The -634CC genotype was significantly associated with high tumor aggressiveness [large tumor size (OR=2.63, 95% CI=1.15, 6.02; P=0.02) and high histologic grade (OR=1.47, 95% CI= 1.06, 2.03; P=0.02)]. The genotypes were not related with other tumor characteristics such as regional or distant metastasis, stage at diagnosis, or estrogen or progesterone receptor status. Our study revealed that the VEGF -634 G/C and +936 C/T gene polymorphisms may be associated with breast cancer in Chinese Han patients.

Abstract 1230: Nicotine induces expression of integrin-linked kinase in human lung carcinoma cells through A7 nAChR-mediated inhibition of AP-2A

We previously demonstrated that nicotine stimulates non small cell lung carcinoma (NSCLC) cell proliferation through nicotinic acetylcholine receptor (nAChR)-mediated induction of fibronectin expression. However, the mechanisms by which this agent affects human lung cancer occurrence and progression remain incompletely elucidated. Here, we show that nicotine increases the expression of integrin-linked kinase (ILK), a unique intracellular adaptor and kinase that has been implicated in the regulation of cancer cell growth/survival. This effect was blocked by the α7 nAChR antagonist, α-bungarotoxin, and by α7 nAChR siRNA. Silencing of ILK blocked the stimulatory effect of nicotine on phosphorylation of the PI3-K downstream target Akt and on cell growth. Furthermore, nicotine increased ILK gene promoter activity through inhibition of transcription factor AP-2α protein expression. Silencing of AP-2α enhanced, while exogenous expression of AP-2α attenuated, the stimulatory effect of nicotine on ILK expression. These findings appear to be relevant in vivo since we found that nicotine treatment increased tumor growth in animal models. Collectively, our results demonstrate that nicotine increases ILK gene expression through α7 nAChR-mediated inhibition of AP-2α followed by stimulation of PI3-K/Akt signaling. In turn, this leads to increased NSCLC cell growth. This study unveils a novel mechanism by which nicotine promotes human lung carcinoma cell growth/survival.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1230.

Abstract 1223: Fibronectin induced lung cancer cell proliferation is dependent on induction of ILK through integrin B1-mediated activation of p38 MAPK and PI3-K

Fibronectin is a multi-functional matrix glycoprotein protein that has been linked to tumor progression. We previously demonstrated that cellular fibronectin (cFN) increased non-small cell lung carcinoma (NSCLC) cell growth through signals mediated by the integrin α5β1. Here, we explore the role of integrin-linked kinase (ILK), an integrin β1 subunit cytoplasmic domain interactor in cFN induced cell growth. We found that cFN increases ILK expression and kinase activity, promotes protein-protein interactions between ILK and integrin β1. Silencing of ILK attenuated the effect of cFN on cell proliferation. Knockdown of the integrin β1 subunit, but not the integrin α5, blocked the effect of cFN on ILK expression. In addition, the inhibitor of p38MAPK, SB239063, and the inhibitor of PI3-K, wortmannin, abrogated the effect of cFN on ILK expression, whereas the inhibitor of ERK, PD98059, had no effect. Taken together, our results demonstrate that fibronectin induces the expression of ILK through integrin β1-mediated signals that include p38 MAPK and PI3-K. This in turn, promotes lung carcinoma cell proliferation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1223.

Nicotine stimulates PPARbeta/delta expression in human lung carcinoma cells through activation of PI3K/mTOR and suppression of AP-2alpha

We previously showed that nicotine stimulates non-small cell lung carcinoma (NSCLC) cell proliferation through nicotinic acetylcholine receptor (nAChR)-mediated signals. Activation of peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) has also been shown to induce NSCLC cell growth. Here, we explore the potential link between nicotine and PPARbeta/delta and report that nicotine increases the expression of PPARbeta/delta protein; this effect was blocked by an alpha7 nAChR antagonist (alpha-bungarotoxin), by alpha7 nAChR short interfering RNA, and by inhibitors of phosphatidylinositol 3-kinase (PI3K; wortmannin and LY294002) and mammalian target of rapamycin (mTOR; rapamycin). In contrast, this effect was enhanced by PUN282987, an alpha7 nAChR agonist. Silencing of PPARbeta/delta attenuated the stimulatory effect of nicotine on cell growth, which was overcome by transfection of an exogenous PPARbeta/delta expression vector. Of note, nicotine induced complex formation between alpha7 nAChR and PPARbeta/delta protein and increased PPARbeta/delta gene promoter activity through inhibition of AP-2alpha as shown by reduced AP-2alpha binding using electrophoretic gel mobility shift and chromatin immunoprecipitation assays. In addition, silencing of Sp1 attenuated the effect of nicotine on PPARbeta/delta. Collectively, our results show that nicotine increases PPARbeta/delta gene expression through alpha7 nAChR-mediated activation of PI3K/mTOR signals that inhibit AP-2alpha protein expression and DNA binding activity to the PPARbeta/delta gene promoter. Sp1 seems to modulate this process. This study unveils a novel mechanism by which nicotine promotes human lung carcinoma cell growth.

[Studies on ultrastructure and histochemistry of Trichomonas vaginalis adhering to vaginal mucosa of rats]

OBJECTIVE

To study interaction between Trichomonas vaginalis and epithelium of genital tract of host as well as the pathogenesis of T. vaginalis.

METHODS

Immunohistochemical technique was used to observe the adhering process of T. vaginalis to vaginal mucosa in rats by transmission and scanning microscopy.

RESULTS

T. vaginalis were shown to be PAS positive and clusters of T. vaginalis were found to adhere to columnar epithelium rich in mucopolysaccharide on the surface of vaginal mucosa as viewed in sections of the middle and upper parts of the orgen. T. vaginalis was positive for cathepsin. And the membrane of epithelial cells was often damaged by the released hydrolase. The parasite was also positive for actin; the microfilament bundles were arranged in reticular form in ameboid T. vaginalis. The latter would penetrate between epithelial cells, and its filiform pseudopodia would invade the interspace of microvilli of the epithelium, to encircle and gradually phagocytize microvilli. Digitiform pseudopodia would insert between epithelial cells and encircle part of them. A few T. vaginalis were found to adhere to the keratinized epithelium between mucosal folds as shown in the sections of the lower part of vagina.

CONCLUSION

T. vaginalis is inclined to parasitise vaginal fornix because the superficial epithelial cells there are rich in mucinogen granules and abundant microvilli exist. After adhering, T. vaginalis releases hydrolase to digest and phagocytize epithelium which may directly damage the epithelium of the genital canal. Moreover, T. vaginalis would take in mucopolysaccharide to affect the normal clearance process of vagina, resulting in inflammation of parasitized tissue. The cytoskeleton, cell coat, polymorphism of pseudopodia and lysosome of T. vaginalis play an important role in the courses of movement, adhesion, encirclement, phagocytosis and digestion.

Ultracytochemical studies on Trichomonas hominis

The results of ultracytochemical studies on Trichomonas hominis showed that ACPase and CMPase were mainly located in the mature face sacs of the primary lysosomes, digestive vacuoles, as well as in the parabasal body. TPPase and NADPase were found in the saccules at the mature face and the intermediate saccules of parabasal body respectively. This study revealed that T. hominis had well-developed parabasal bodies. Negative COase and catalase reactions indicated that T. hominis lacked both mitochondria and microbody. Hydrogenosome was stained well with the Ur-Pb-Cu impregnation technique.

[An electron microscopic study on the ultrastructure and enzyme cytochemistry of Pseudomonas putrefaciens]

In this paper, PTA staining, ultrathin sectioning and electron microscopic enzyme cytochemistry techniques were used to study the ultrastructure, as well as reactivity and localization of catalase and peroxidase in Ps. putrefaciens. Its ultrastructure is similar to that of other gram-negative bacilli. Catalase is distributed in the cytoplasm, while peroxidase localized at cytoplasmic membrane and mesosomes.