Association between being breastfed in infancy and adult colorectal cancer risk among Japanese men and women.

It has been postulated that being breastfed in infancy affects not only health status in childhood but also disease risk in adulthood. To investigate the association of being breastfed with the risks of adult colorectal cancer and benign tumor, we conducted a case-control study including 1190 colorectal cancer and 1585 benign tumor cases and 5301 controls, admitted to a single hospital in Miyagi Prefecture, Japan, between 1997 and 2013. History of having been breastfed was assessed using a self-administered questionnaire, and odds ratios (ORs) were estimated using unconditional logistic regression. There was no association between being breastfed and colorectal cancer risk (breastfed versus formula-only fed, OR = 1.21; 95% CI 0.87-1.67). There was also no association with the risk of benign tumor (OR = 1.04). On the other hand, analyses stratified by sex and birth year found heterogeneous associations. Women born after 1950 who had been breastfed tended to have increased risks of colorectal cancer (OR = 1.58) and benign tumor (OR = 1.51) relative to those who had been formula-only fed, although not statistically significant. In men born after 1950, being breastfed was associated with a significantly decreased risk of benign tumor (OR = 0.57; 95% CI 0.33-0.98).

TP53 signature diagnostic system using multiplex reverse transcription-polymerase chain reaction system enables prediction of prognosis of breast cancer patients.

BACKGROUND: TP53 status based on TP53 signature, a gene expression profile to determine the presence or absence of TP53 mutation, is an independent prognostic factor of breast cancer. The purpose of this study was to develop a simple diagnostic system for TP53 signature status. METHODS: We developed a multiplex reverse transcription-polymerase chain reaction system to determine TP53 status. Based on this system, prospectively collected 189 patients with stage I and II breast cancer were determined to have TP53 mutant signature or TP53 wild-type signature. The prognostic significance of the TP53 signature by the diagnostic system was analyzed. RESULTS: The diagnostic accuracy of TP53 status and reproducibility of this diagnosis system was confirmed. Using the diagnostic system, 89 patients were classified as TP53 mutant signature and the remaining 100 cases were classified as TP53 wild-type signature. Recurrence-free survival (RFS) among patients with TP53 mutant signature was significantly shorter than that among those with TP53 wild-type signature. On univariate and multivariate analyses, the TP53 signature status was an independent predictor of RFS. RFS among patients with TP53 mutant signature was significantly shorter than that among those with TP53 wild-type signature in a cohort of estrogen receptor-positive breast cancer. Although a difference was not significant, no recurrent cases was observed in TP53 wild-type signature group in triple negative breast cancer. CONCLUSION: This simple and precise diagnostic system to determine TP53 signature status may help in prognostic assessment, therapeutic decision-making, and treatment optimization in patients with breast cancer.

Alcohol consumption and survival after breast cancer diagnosis in Japanese women: A prospective patient cohort study.

BACKGROUND: It is unclear whether alcohol consumption may impact survival after breast cancer diagnosis. To clarify the association between pretreatment alcohol consumption and survival in breast cancer patients, a prospective patient cohort study was conducted. METHODS: The cohort comprised 1,420 breast cancer patients diagnosed during 1997-2013 at a single institute in Japan. Alcohol drinking and other lifestyle factors were assessed by questionnaire survey at the initial admission. The patients were followed until December 31, 2016. The crude associations of pretreatment alcohol intake with survival were evaluated by Kaplan-Meier analysis. The Cox proportional hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) controlled by confounders. RESULTS: During a median follow-up period of 8.6 years, 261 all-cause and 193 breast cancer-specific deaths were documented. Survival curves showed that ever-drinkers tended to have better survival than never-drinkers (breast cancer-specific survival, log-rank p = 0.0381). Better survival was also observed for light drinkers with an intake of <5.0 g per day. In the Cox model, ever-drinking was associated with a decreased risk of all-cause (HR: 0.75; 95% CI: 0.54-1.05) and breast cancer-specific death (HR: 0.68; 95% CI: 0.46-0.99). Light drinkers had a lower risk of breast cancer-specific death (frequency of drinking, HR = 0.57 for occasional or 1-2 times per week and 0.72 for 3-7 times per week; amount of alcohol consumed per day, HR = 0.57 for <5.0 g and 0.68 for ≥5.0 g compared with never-drinking). In terms of hormone receptor status, a significantly decreased risk of death associated with ever-drinking was observed among women with receptor-negative cancer (ER-/PR-, HR = 0.41; 95% CI: 0.20-0.84 for breast cancer-specific death). CONCLUSIONS: Pretreatment, i.e., pre-diagnosis alcohol consumption is unlikely to have an adverse effect on survival after breast cancer diagnosis. Light alcohol consumption may have a beneficial effect on patient survival.

Reproductive history and breast cancer survival: a prospective patient cohort study in Japan.

BACKGROUND: Reproductive factors may influence breast cancer progression and patient survival; however, evidence has been limited. METHODS: The associations of reproductive factors with tumor characteristics and patient survival were analyzed among 1468 breast cancer patients diagnosed during 1997-2013 at a single institute in Japan. The patients were followed until 2016. During a median follow-up period of 8.6 years, 272 all-cause and 199 breast cancer deaths were documented. RESULTS: In case-case comparisons, later age at menarche was inversely associated with advanced tumors. Nulliparous patients tended to have receptor-positive [estrogen receptor (ER)+ or progesterone receptor (PR)+] tumors. Conversely, the Cox proportional-hazards model including adjustment for tumor characteristics revealed U-shaped relationship between parity number and the risk of all-cause death among the patients overall [hazard ratio (HR) = 2.10 for nulliparous, 1.28 for 2, and 1.50 for ≥ 3 vs. one child]. According to hormone receptor, later age at menarche and later age at last birth were positively associated with the risk of all-cause death among patients with ER- and PR- cancer (menarche, HR = 2.18 for ≥ 15 vs. ≤ 12 years, ptrend = 0.03; last birth, HR = 3.10 for ≥ 35 vs. ≤ 29 years, ptrend = 0.01). A shorter time since last birth was associated with the risk of death among receptor-positive patients (HR = 5.72 for ≤ 4 vs. ≥ 10 years, ptrend = 0.004). CONCLUSION: The results indicate that the timing of menarche and parity have significant effects on patient survival, providing clues for understanding the association between women's life course and breast cancer outcome.

Loss of protein phosphatase 6 in mouse keratinocytes enhances K-rasG12D -driven tumor promotion.

Here, we address the function of protein phosphatase 6 (PP6) loss on K-ras-initiated tumorigenesis in keratinocytes. To do so, we developed tamoxifen-inducible double mutant (K-rasG12D -expressing and Ppp6c-deficient) mice in which K-rasG12D expression is driven by the cytokeratin 14 (K14) promoter. Doubly-mutant mice showed early onset tumor formation in lips, nipples, external genitalia, anus and palms, and had to be killed by 3 weeks after induction by tamoxifen, while comparably-treated K-rasG12D -expressing mice did not. H&E-staining of lip tumors before euthanasia revealed that all were papillomas, some containing focal squamous cell carcinomas. Immunohistochemical analysis of lips of doubly-mutant vs K-rasG12D mice revealed that cell proliferation and cell size increased approximately 2-fold relative to K-rasG12D -expressing mutants, and epidermal thickness of lip tissue greatly increased relative to that seen in K-rasG12D -only mice. Moreover, AKT phosphorylation increased in K-rasG12D -expressing/Ppp6c-deficient cells, as did phosphorylation of the downstream effectors 4EBP1, S6 and GSK3, suggesting that protein synthesis and survival signals are enhanced in lip tissues of doubly-mutant mice. Finally, increased numbers of K14-positive cells were present in the suprabasal layer of doubly-mutant mice, indicating abnormal keratinocyte differentiation, and γH2AX-positive cells accumulated, indicating perturbed DNA repair. Taken together, Ppp6c deficiency enhances K-rasG12D -dependent tumor promotion.

Associations of cigarette smoking and alcohol drinking with stomach cancer survival: A prospective patient cohort study in Japan.

Cigarette smoking and alcohol drinking may affect the prognosis of stomach cancer, but evidence has been inconsistent. We investigated the associations between pretreatment smoking and alcohol drinking and the risk of all-cause and stomach cancer death among 1,576 patients with histologically confirmed stomach cancer diagnosed during 1997-2010 at a single hospital in Japan. Histories of smoking and alcohol drinking were assessed using a self-administered questionnaire. The patients were followed until December 31, 2013. The Cox proportional hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During 9,625.1 person-years, 670 all-cause and 419 stomach cancer deaths were documented. Among the patients overall, ever-drinking was significantly associated with an increased risk of all-cause death (HR: 1.25; 95% CI: 1.03-1.51), but not stomach cancer death. Positive linear associations with the frequency of drinking (ptrend = 0.02) and the amount of alcohol consumed per day (ptrend = 0.03) were observed for the risk of all-cause death. Ever-smoking was not related to either the risk of all-cause or stomach cancer death. Conversely, among the patients who underwent curative resection, a significant positive association was found between ever-smoking and the risk of stomach cancer death (HR: 2.44; 95% CI: 1.17-5.08). A positive association was also found for earlier age at start of smoking (ptrend = 0.0046). Pretreatment smoking and alcohol drinking have significant effects on stomach cancer survival. Lifestyle adjustments throughout life may improve survival.

Molecular and clinical features of the TP53 signature gene expression profile in early-stage breast cancer.

PURPOSE: TP53 signature has a robust predictive performance for prognosis in early-stage breast cancer, but the experiment that reported this relied on public microarray data and fresh-frozen samples. Before TP53 signature can be used in a clinical setting, a simple and low-cost diagnostic system using formalin-fixed paraffin-embedded (FFPE) samples is needed. New treatments based on the biological characteristics of TP53 signature are expected to follow. EXPERIMENTAL DESIGN: TP53 signature was evaluated in 174 FFPE early breast cancer specimens using digital quantification via the nCounter technique (NanoString). Patients were classified as TP53 signature mutant type (n = 64) or wild type (n = 110). Predictive power of TP53 signature was compared with those of other gene expression signatures in 153 fresh-frozen samples of the same cohort by RNA-seq. The molecular features of TP53 signature were elucidated using TCGA omics data and RNA-seq data to explore new therapeutic strategies for patients with TP53 signature mutant type. RESULTS: TP53 signature was a strong predictor of prognosis and was also more accurate than other gene expression signatures and independent of other clinicopathological factors. TCGA data analysis showed that risk score of TP53 signature was an index of chromosomal and genomic instability and that TP53 signature mutant type was associated with higher PD-L1 expression, variation in copy numbers, and numbers of somatic mutations. CONCLUSIONS: TP53 signature as diagnosed using the nCounter system is not only a robust predictor of prognosis but also a potential predictor of responsiveness to immune checkpoint inhibitors.

Alcohol Consumption and Breast Cancer Risk According to Hormone Receptor Status in Japanese Women: A Case-Control Study.

Alcohol consumption is a risk factor for breast cancer in Western countries, but few studies have evaluated the risk for Japanese women, who have a relatively low alcohol intake. This case-control study investigated the association of alcohol consumption with breast cancer risk according to estrogen-receptor and progesterone-receptor (ER/PgR) status in Japanese women. From female patients aged 30 years and over admitted to a single hospital in Japan between 1997 and 2011, 1,256 breast cancer cases (669 ER+/PgR+, 162 ER+/PgR-, 21 ER-/PgR+, 305 ER-/PgR-, and 99 missing) and 2,933 controls were selected. Alcohol-related measures were assessed using a self-administered questionnaire. Unconditional logistic regression analysis was performed. Alcohol-related measures were not associated with breast cancer risk among the women overall. Moreover, no association was observed between ever drinking and the risk of a concordant receptor subtype (ER+/PgR+ or ER-/PgR-). Conversely, ever drinking was inversely associated with the risk of discordant subtype (ER+/PgR-, odds ratio (OR) = 0.63, 95% confidence interval (CI): 0.41-0.95; ER-/PgR+, OR = 0.44, 95% CI: 0.14-1.42). For ER+/PgR-, an inverse association with the amount of alcohol consumed per day was observed (P for trend = 0.04), and this inverse association was limited to premenopausal women. Alcohol consumption may have differential effects on concordant and discordant receptor subtypes of breast cancer. In view of the low frequency of discordant subtype in Japanese women and their relatively low alcohol intake, our findings may provide a clue for elucidating the etiology of breast cancer rather than for preventing discordant subtype.

Quantitative diagnostic imaging of cancer tissues by using phosphor-integrated dots with ultra-high brightness.

The quantitative sensitivity and dynamic range of conventional immunohistochemistry (IHC) with 3,3'-diaminobenzidine (IHC-DAB) used in pathological diagnosis in hospitals are poor, because enzyme activity can affect the IHC-DAB chromogenic reaction. Although fluorescent IHC can effectively increase the quantitative sensitivity of conventional IHC, tissue autofluorescence interferes with the sensitivity. Here, we created new fluorescent nanoparticles called phosphor-integrated dots (PIDs). PIDs have 100-fold greater brightness and a more than 300-fold greater dynamic range than those of commercially available fluorescent nanoparticles, quantum dots, whose fluorescence intensity is comparable to tissue autofluorescence. Additionally, a newly developed image-processing method enabled the calculation of the PID particle number in the obtained image. To quantify the sensitivity of IHC using PIDs (IHC-PIDs), the IHC-PIDs method was compared with fluorescence-activated cell sorting (FACS), a method well suited for evaluating total protein amount, and the two values exhibited strong correlation (R = 0.94). We next applied IHC-PIDs to categorize the response to molecular target-based drug therapy in breast cancer patients. The results suggested that the PID particle number estimated by IHC-PIDs of breast cancer tissues obtained from biopsy before chemotherapy can provide a score for predicting the therapeutic effect of the human epidermal growth factor receptor 2-targeted drug trastuzumab.

Minimal impact of postmastectomy radiation therapy on locoregional recurrence for breast cancer patients with 1 to 3 positive lymph nodes in the modern treatment era.

INTRODUCTION: Given modern treatment strategies, controversy remains regarding whether postmastectomy radiation therapy (PMRT) is necessary for breast cancer patients with 1-3 positive axillary lymph nodes (ALN). Our aim was to assess the significance of PMRT in the modern treatment era for these patients. MATERIAL AND METHODS: We have conducted the retrospective multicenter study and identified 658 patients with 1-3 positive ALN who were treated with mastectomy and ALN dissection between 1999 and 2012. Propensity score weighting was used to minimize the influence of confounding factors between the PMRT and no-PMRT groups. The variables including tumor size, lymph nodes status, skin and/or muscle invasion, histological grade, lymphovascular invasion and ER positivity which were statistically unbalanced between the groups were used to define the propensity scores. RESULTS: The median follow-up time was 7.3 years. In the modern era (2006-2012), no significant difference in locoregional recurrence (LRR)-free survival was noted between the PMRT and no-PMRT groups (P = 0.3625). The 8-year LRR-free survival rates of the PMRT and no-PMRT groups were 98.2% and 95.3%, respectively. After matching patients by propensity scores, the PMRT group, compared to the no-PMRT group, exhibited significantly better locoregional control (P = 0.0366) in the entire cohort. The 10-year LRR-free survival rates were 97.8% and 88.4% in the PMRT and no-PMRT groups, respectively. In contrast, no significant difference in LRR-free survival was noted between the PMRT and no-PMRT groups in the modern era (P = 0.5298). The 8-year LRR-free survival rates of patients treated in the modern era were approximately the same between the groups (98.0% and 95.7% in the PMRT and no-PMRT groups, respectively). Particularly, LRR-free survival of HER2 positive breast cancer significantly improved in the modern treatment era, compared with that of the old treatment era (P = 0.0349). CONCLUSION: PMRT had minimal impact on LRR for breast cancer patients with 1-3 positive ALN in the modern treatment era.

Drug delivery of oral anti-cancer fluoropyrimidine agents.

INTRODUCTION: Sixty years since its introduction, 5-FU still forms the core of chemotherapy regimens for many types of malignancies. 5-FU is a time-dependent drug but is rapidly degraded in plasma by dihydropyrimidine dehydrogenase (DPD). Although originally developed in an intravenous form, 5-FU oral prodrugs were developed with the goal of improving efficacy and minimizing toxicity as well as to capitalize on the advantages of oral drug administration. The inactive 5-FU prodrug is gradually converted into the active form in the systemic circulation. UFT, S-1, and capecitabine are oral 5-FU prodrugs currently in clinical use. However, the efficacy of 5-FU can be further improved by its combination with DPD inhibitors and biochemical modulators, such as uracil and leucovorin, in addition to modifying administration schedules. Areas covered: We focused on the drug delivery of oral 5-FU prodrugs, their pharmacokinetics, and the development of DPD inhibitors. Since oral 5-FU prodrugs have been formulated into combination drugs, we also discussed the regulatory approval of combination drugs. Expert opinion: Many regimens that include intravenously administered 5-FU can be replaced by oral 5-FU prodrugs. Patients would benefit from development of combination 5-FU oral prodrug formulations and its associated path through the combination drug regulatory approval process.

Associations of obesity and physical activity with serum and intratumoral sex steroid hormone levels among postmenopausal women with breast cancer: analysis of paired serum and tumor tissue samples.

PURPOSE: It has been hypothesized that intratumoral estrogens may play important roles in the growth of breast cancer. However, few studies have investigated such intratumoral hormones, or their association with risk factors of breast cancer. METHODS: In this cross-sectional study, hormone levels in paired serum and tumor tissue samples from 146 postmenopausal women with breast cancer were measured by liquid chromatography-tandem mass spectrometry and compared between estrogen/progesterone (ER/PgR) subtypes. The associations of risk factors including body mass index (BMI) and other lifestyle factors with these hormone levels were investigated using analysis of covariance. RESULTS: The level of estradiol (E2) in tumor tissue was extremely high in women with ER+ (geometric mean 95.6 pg/g) relative to women with ER-/PgR- (8.9 pg/g), whereas serum E2 level did not differ much between the two groups (3.1 and 2.8 pg/ml, respectively). Serum levels of precursors for E2, including testosterone (T) and androstenedione (Adione), and tissue Adione level, were high among women with ER+. After adjustment for confounding variables, BMI was found to be positively associated with tissue levels of E2, estrone (E1), T, and Adione among women with ER+ (P trend < 0.0001 for E2; 0.0016 for E1; 0.0002 for T; and 0.03 for Adione). CONCLUSION: The data suggest that tissue E2 is related to the growth of receptor-positive breast cancer and that risk factors such as BMI affect tissue levels of E2 and its precursors. Understanding of hormonal environments within tumor tissue may be important for elucidating hormonal etiology of breast cancer and improving the prognosis of patients.

Loss of protein phosphatase 6 in mouse keratinocytes increases susceptibility to ultraviolet-B-induced carcinogenesis.

We previously reported that deficiency in the gene encoding the catalytic subunit of protein phosphatase 6 (Ppp6c) predisposes mouse skin tissue to papilloma formation initiated by DMBA. Here, we demonstrate that Ppp6c loss acts as a tumor promoter in UVB-induced squamous cell carcinogenesis. Following UVB irradiation, mice with Ppp6c-deficient keratinocytes showed a higher incidence of skin squamous cell carcinoma than did control mice. Time course experiments showed that following UVB irradiation, Ppp6c-deficient keratinocytes upregulated expression of p53, PUMA, BAX, and cleaved caspase-3 proteins. UVB-induced tumors in Ppp6c-deficient keratinocytes exhibited a high frequency of both p53- and γH2AX-positive cells, suggestive of DNA damage. Epidemiological and molecular data strongly suggest that UVB from sunlight induces p53 gene mutations in keratinocytes and is the primary causative agent of human skin cancers. Our analysis suggests that PP6 deficiency underlies molecular events that drive outgrowth of initiated keratinocytes harboring UVB-induced mutated p53. Understanding PP6 function in preventing UV-induced tumorigenesis could suggest strategies to prevent and treat this condition.

Smoking and survival after breast cancer diagnosis in Japanese women: A prospective cohort study.

The results of previous studies investigating whether there is an association between active smoking and risk of death among breast cancer patients have been inconsistent. We investigated the association between active and passive smoking and risk of all-cause and breast cancer-specific death among female breast cancer patients in relation to menopausal and tumor estrogen/progesterone receptor (ER/PR) status. The present study included 848 patients admitted to a single hospital in Japan from 1997 to 2007. Active or passive smoking status was assessed using a self-administered questionnaire. The patients were followed until 31 December 2010. We used a Cox proportional-hazard model to estimate hazard ratios (HR). During a median follow-up period of 6.7 years, 170 all-cause and 132 breast cancer-specific deaths were observed. Among premenopausal patients, current smokers showed a non-significant higher risk of all-cause and breast cancer-specific death. A duration of smoking >21.5 years was positively associated with all-cause (HR = 3.09, 95% confidence interval [CI], 1.17-8.20) and breast cancer-specific death (HR = 3.35, 95% CI: 1.22-9.23, Ptrend  = 0.035) among premenopausal patients. In premenopausal patients with ER+ or PR+ tumors, there was some suggestion that a longer duration of smoking was associated with higher risk of all-cause and breast cancer-specific death. Passive smoking demonstrated no significant risk. Our results suggest that a longer duration of active smoking is associated with an increased risk of all-cause and breast cancer-specific death among premenopausal patients, possibly with hormonal receptor-positive tumors. Breast cancer patients should be informed about the importance of smoking cessation.

Immunolocalization of thymidylate synthase as a favorable prognostic marker in estrogen receptor-positive breast carcinoma.

BACKGROUND: Thymidylate synthase (TS) is an enzyme involved in DNA synthesis, and it is a target for 5-fluorouracil. Previous studies have demonstrated that TS is a potent estrogen-induced gene in breast carcinoma cells, suggesting the importance of TS in estrogen-receptor (ER)-positive breast carcinoma. TS immunolocalization has been reported previously, but the clinicopathological significance of TS in ER-positive breast carcinoma still remains unclear. PATIENTS AND METHODS: We immunolocalized TS in 178 breast carcinoma tissues in total, and examined its significance according to the ER-status. RESULTS: TS status was positive in 58% of ER-positive ductal carcinoma in situ (DCIS) cases, and it was significantly associated with the Ki-67 and progesterone receptor (PR). Moreover, in ER-positive DCIS patients who received aromatase inhibitor (AI) before surgery, TS immunoreactivity was significantly decreased after AI treatment. In ER-positive invasive ductal carcinoma (IDC) cases, TS status was significantly associated with PR, and it turned out an independent favorable prognostic factor for recurrence of the patients by multivariate analysis. On the other hand, TS status was positively correlated with pathological T factor in ER-negative IDC cases, and tended to have a worse prognosis for disease-free survival of the patients. CONCLUSION: These results suggest that TS expression is mainly regulated by estrogen in ER-positive breast carcinoma and is associated with estrogen-mediated proliferation. TS status is a favorable prognostic factor in ER-positive IDC patients, which is different from the ER-negative cases.

Personality and breast cancer risk and survival: the Miyagi cohort study.

It has long been hypothesized that personality is associated with breast cancer risk and survival. The present population-based prospective cohort study in Japan tested this hypothesis. To investigate the association of personality with breast cancer risk, a total of 15,107 women aged 40-64 years who completed the Eysenck Personality Questionnaire-Revised (EPQ-R) Short Form were followed from 1990 to 2007. To assess the association of personality with survival after breast cancer, 250 identified cases were further followed up from the date of diagnosis to 2008, and 45 all-cause deaths were documented. Study subjects were categorized into four groups based on the quartile points of scores ranging between 0 and 12 on each EPQ-R subscale (extraversion, neuroticism, psychoticism, and lie), and the hazard ratio (HR) for each category was computed using the lowest category as reference. Multivariate analysis revealed no association between any of the four personality subscales and the risk of breast cancer. In the analysis on survival, no significant association was found between any of these subscales and the risk of death, although breast cancer cases with a higher score of extraversion tended to have a lower risk of death (P for trend = 0.07; HR for highest score level = 0.38). Exclusion of 32 cases diagnosed in the first 3 years of follow-up did not largely change the results with regard to either breast cancer risk or survival. The present findings suggest that personality does not impact significantly on the development and progression of breast cancer.

The use of natural products in colorectal cancer drug discovery.

INTRODUCTION: Natural products (NPs) are evolutionarily designed and contain more complex and challenging structures than synthetic compounds. Since the 1980s, the pharmaceutical industry has gradually shifted to a strategy of developing targeted agents by screening libraries of synthetic compounds. However, NPs have recently received renewed focus as a rich repository for drug discovery. Irinotecan was developed as a derivative of camptothecin and was applied in standard regimens for metastatic colorectal cancer (CRC) worldwide. Additionally, polysaccharide K is approved for CRC in Japan and Taiwan in combination with cytotoxic agents. However, after the approval of irinotecan in 1996, no anti-cancer agents derived from NPs have been approved for CRC. AREAS COVERED: This review discusses NPs that are currently under investigation for the treatment of CRC. In addition, other NPs derived as purified ingredients and crude extracts are listed and also discussed. EXPERT OPINION: The use of NPs for the discovery of anti-cancer agents has not been fully investigated. New technologies that are currently applied for synthetic compounds may be utilized for anti-cancer drug discovery including NPs for CRC.

Family history, body mass index and survival in Japanese patients with stomach cancer: a prospective study.

Family history and nutritional status may affect the long-term prognosis of stomach cancer, but evidence is insufficient and inconsistent. To clarify the prognostic factors of stomach cancer, we conducted a prospective study of 1,033 Japanese patients with histologically confirmed stomach cancer who were admitted to a single hospital between 1997 and 2005. Family history of stomach cancer and pretreatment body mass index (BMI) were assessed using a self-administered questionnaire. Clinical data were retrieved from a hospital-based cancer registry. All patients were completely followed up until December, 2008. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated according to family history in parents and siblings and BMI category. During a median follow-up of 5.3 years, 403 all-cause and 279 stomach cancer deaths were documented. Although no association with family history was observed in the patients overall, analysis according to age group found an increased risk of all-cause death associated with a history in first degree relatives (HR = 1.61, 95% CI: 0.93-2.78, p = 0.09) and with a parental history (HR = 1.86, 95% CI: 1.06-3.26) among patients aged under 60 years at diagnosis. BMI was related to all-cause and stomach cancer death among patients aged 60 and over, showing a J-shaped pattern (HR of all-cause death = 2.28 for BMI < 18.5; HR = 1.61 for 25 ≤ vs. ≥ 23.0 to < 25.0 kg/m(2)). A family history of stomach cancer, especially parental history, may affect mortality among younger stomach cancer patients, whereas nutritional status may be a prognostic factor in older patients.

Increased androgen receptor activity and cell proliferation in aromatase inhibitor-resistant breast carcinoma.

Aromatase inhibitors (AI) are commonly used to treat postmenopausal estrogen-receptor (ER)-positive breast carcinoma. However, resistance to AI is sometimes acquired, and the molecular mechanisms underlying such resistance are largely unclear. Recent studies suggest that AI treatment increases androgen activity during estrogen deprivation in breast carcinoma, but the role of the androgen receptor (AR) in breast carcinoma is still a matter of controversy. The purpose of this study is to examine the potential correlation between the AR- and AI-resistant breast carcinoma. To this end, we performed immunohistochemical analysis of 21 pairs of primary breast carcinoma and corresponding AI-resistant recurrent tissue samples and established two stable variant cell lines from ER-positive T-47D breast carcinoma cell line as AI-resistance models and used them in in vitro experiments. Immunohistochemical analysis demonstrated that the expression of prostate-specific antigen (PSA) and Ki-67 were significantly higher and ER and progesterone receptor (PR) were lower in recurrent lesions compared to the corresponding primary lesions. Variant cell lines overexpressed AR and PSA and exhibited neither growth response to estrogen nor expression of ER. Androgen markedly induced the proliferation of these cell lines. In addition, the expression profile of androgen-induced genes was markedly different between variant and parental cell lines as determined by microarray analysis. These results suggest that in some cases of ER-positive breast carcinoma, tumor cells possibly change from ER-dependent to AR-dependent, rendering them resistant to AI. AR inhibitors may thus be effective in a selected group of patients.

The preclinical development of regorafenib for the treatment of colorectal cancer.

INTRODUCTION: The RAS-RAF-MEK-ERK pathway is one of the best characterized kinase cascades. During the exploration of small molecules that inhibit RAF1 kinase, regorafenib (BAY 73-4506) was discovered as a multikinase inhibitor which demonstrated anti-cancer, anti-angiogenic, and apoptotic activities in metastatic colorectal cancer. This was not the first multikinase inhibitor discovered for the disease; indeed, before regorafenib was approved by FDA as a multikinase inhibitor for metastatic colorectal cancer in 2012, sorafenib (BAY 43-9006) had already been developed to be the first in the world as a multikinase inhibitor for malignancy. Indeed, the only difference between the two compounds is fluorine bound to its proximal phenyl ring although the end result is a considerably different profile, both as a kinase inhibitor as well as in its clinical application. AREAS COVERED: In this drug discovery case history, the authors review the design, discovery, and development of both regorafenib and sorafenib from back in the 1990s. Furthermore, the authors highlight the drug's anti-cancer and anti-angiogenic properties as well as its efficacy, safety pharmacology and toxicology based on FDA documents. EXPERT OPINION: In order to better predict the efficacy of kinase inhibitors and to utilize them more efficiently, our understanding of drug discovery, the approaches for kinase profiling, and technologies needed for their development are paramount. Indeed, the authors believe that the field should better explore the use of predictive biomarkers that might be able to better assess these therapeutics. Pharmaceutical scientists must also consider the cost effectiveness of the targeted agents developed as a number of the drugs developed are very expensive.