Impact of dietary vitamin D on initiation and progression of oral cancer

Calcitriol, the active metabolite of vitamin D, has been widely studied for its preventive and therapeutic activity against several cancers including oral squamous cell carcinoma (OSCC). However, the impact of dietary vitamin D supplementation on initiation and progression of OSCC is unclear. To address this gap in knowledge, we conducted preclinical trials using the 4-nitroquinoline-1-oxide 4NQO carcinogen model of oral carcinogenesis. Female C57BL/6 mice were maintained on one of three vitamin D diets [25 IU, 100 IU, 10,000 IU] and exposed to 4NQO in drinking water for 16 weeks followed by regular water for 10 weeks. Body weight measurements obtained through the study duration did not reveal any differences between the three diets. Animals on 100 IU diet showed lower incidence of high-grade dysplasia/OSCC and higher CD3 + T cells compared to animals on 25 IU and 10,000 IU diets. Serum 25OHD₃ levels were highest in animals on 10,000 IU diet at week 0 prior to carcinogen exposure but showed ∼50 % reduction at week 26. Histologic evaluation revealed highest incidence of OSCC in animals maintained on 10,000 IU diet. Animals on 100 IU and 10,000 IU diets showed higher vitamin D receptor VDR and CYP24A1 immunostaining in high-grade dysplastic lesions and OSCC compared to normal tongue. Validation studies performed in a 4NQO-derived OSCC model showed that short-term treatment of animals on a 25 IU diet with calcitriol significantly inhibited tumor growth compared to controls but did not affect tumor growth in animals on reference diet 1000 IU. Collectively, our results highlight the complex dynamics between vitamin D status and oral carcinogenesis. Our observations also suggest that therapeutic benefits of short-term calcitriol treatment may be more pronounced in vitamin D deficient hosts.

Updated Results of PURE-01 with Preliminary Activity of Neoadjuvant Pembrolizumab in Patients with Muscle-invasive Bladder Carcinoma with Variant Histologies

BACKGROUND

Patients with predominant variant histology (VH) of bladder tumors, defined as involving >50 % of the tumor specimens, are typically excluded from clinical trials, and for these patients, the efficacy of standard chemotherapy is limited.

OBJECTIVE

To evaluate the activity of preoperative pembrolizumab in patients with muscle-invasive bladder carcinoma (MIBC) and VH, enrolled in PURE-01 study (NCT02736266).

DESIGN, SETTING, AND PARTICIPANTS

In the open-label, single-arm, phase 2 PURE-01 study, three courses of 200 mg pembrolizumab preceding radical cystectomy (RC) were administered in T2-4aN0M0 MIBC patients. The amended study design included patients with predominant VH.

INTERVENTION

Neoadjuvant pembrolizumab and RC.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Pathological complete response (pT0) in intention-to-treat population was the primary endpoint. Biomarker analyses included programmed cell-death ligand-1 (PD-L1) expression using the combined positive score (CPS; Dako 22C3 antibody) and comprehensive genomic profiling (FoundationOne assay). Multivariable logistic regression analyses (MVAs) evaluated the histological category (predominant VH vs nonpredominant VH vs pure urothelial carcinoma), tumor mutational burden (TMB) and CPS in association with the pathological response.

RESULTS AND LIMITATIONS

From February 2017 to June 2019, 114 patients were enrolled; 34 (30%) of them presented with VH, including 19 (17%) with predominant VH. In total, the pT0 rate was 37% (95% confidence interval [CI]: 28-46) and the pT ≤ 1 rate was 55% (95% CI: 46-65). The majority of predominant VH patients presented with squamous-cell carcinoma (SCC; N = 7), and six of seven (86%) had downstaging to pT ≤ 1, with one pT0; two of three lymphoepithelioma-like (LEL) variants had a pT0 response. None of the remaining nine predominant VHs had a response. On MVA, TMB and CPS were associated with both the pT0 and the pT ≤ 1 response, regardless of tumor histology.

CONCLUSIONS

The updated PURE-01 results confirm the activity of neoadjuvant pembrolizumab in MIBC. Patients with SCC and LEL features may be suitable for neoadjuvant immunotherapy trials. CPS and TMB are the key response predictors irrespective of the histological subtypes.

PATIENT SUMMARY

In the PURE-01 study, we have preliminarily evaluated the activity of neoadjuvant pembrolizumab in patients with predominant variant histology (VH). Of these patients, those harboring squamous-cell carcinoma or a lymphoepithelioma-like variant feature had major, although preliminary, pathological responses compared with those with other predominant VHs. Expression of programmed cell-death ligand-1 and tumor mutational burden may predict the pathological response to pembrolizumab, and provide a rationale for selecting patients according to these features instead of the histological bladder cancer subtypes.

Dietary-phytochemical mediated reversion of cancer-specific splicing inhibits Warburg effect in head and neck cancer

BACKGROUND

The deregulated alternative splicing of key glycolytic enzyme, Pyruvate Kinase muscle isoenzyme (PKM) is implicated in metabolic adaptation of cancer cells. The splicing switch from normal PKM1 to cancer-specific PKM2 isoform allows the cancer cells to meet their energy and biosynthetic demands, thereby facilitating the cancer cells growth. We have investigated the largely unexplored epigenetic mechanism of PKM splicing switch in head and neck cancer (HNC) cells. Considering the reversible nature of epigenetic marks, we have also examined the utility of dietary-phytochemical in reverting the splicing switch from PKM2 to PKM1 isoform and thereby inhibition of HNC tumorigenesis.

METHODS

We present HNC-patients samples, showing the splicing-switch from PKM1-isoform to PKM2-isoform analyzed via immunoblotting and qRT-PCR. We performed methylated-DNA-immunoprecipitation to examine the DNA methylation level and chromatin-immunoprecipitation to assess the BORIS (Brother of Regulator of Imprinted Sites) recruitment and polII enrichment. The effect of dietary-phytochemical on the activity of denovo-DNA-methyltransferase-3b (DNMT3B) was detected by DNA-methyltransferase-activity assay. We also analyzed the Warburg effect and growth inhibition using lactate, glucose uptake assay, invasion assay, cell proliferation, and apoptosis assay. The global change in transcriptome upon dietary-phytochemical treatment was assayed using Human Transcriptome Array 2.0 (HTA2.0).

RESULTS

Here, we report the role of DNA-methylation mediated recruitment of the BORIS at exon-10 of PKM-gene regulating the alternative-splicing to generate the PKM2-splice-isoform in HNC. Notably, the reversal of Warburg effect was achieved by employing a dietary-phytochemical, which inhibits the DNMT3B, resulting in the reduced DNA-methylation at exon-10 and hence, PKM-splicing switch from cancer-specific PKM2 to normal PKM1. Global-transcriptome-analysis of dietary-phytochemical-treated cells revealed its effect on alternative splicing of various genes involved in HNC.

CONCLUSION

This study identifies the epigenetic mechanism of PKM-splicing switch in HNC and reports the role of dietary-phytochemical in reverting the splicing switch from cancer-specific PKM2 to normal PKM1-isoform and hence the reduced Warburg effect and growth inhibition of HNC. We envisage that this approach can provide an effective way to modulate cancer-specific-splicing and thereby aid in the treatment of HNC.

Prognostic factors associated with achieving total oral diet after glossectomy with microvascular free tissue transfer reconstruction

OBJECTIVE

Primary surgery followed by adjuvant therapy is the current standard of care in the multidisciplinary management of squamous cell carcinoma (SCC) of the oral tongue. Additionally, salvage glossectomy is used to treat recurrent base of tongue SCC. Microvascular free tissue transfer reconstruction (MVFTT) is utilized to maximize functional outcomes such as swallowing. We sought to identify prognostic factors related to achievement of a total oral diet in patients that underwent glossectomy with MVFTT.

METHODS

Retrospective review at a tertiary care center from 2010 to 2015.

RESULTS

200 patients (69% male, mean age 60 years) met inclusion criteria. Extent of glossectomy was categorized as partial or hemiglossectomy (39%), tongue base resection with or without hemi-oral glossectomy (23%), composite resection with mandibulectomy (18%), and subtotal or total glossectomy (21%). Flap success rate was 96%. Median follow-up time was 14  months. A total oral diet was achieved by 49% of patients with median time to achievement of 31  days (IQR 9-209). Multivariate analysis identified body mass index  < 25 kg/m2, prior radiation therapy, adjuvant chemoradiation, and resection requiring subtotal or total glossectomy or concurrent mandibulectomy as independent risk factors for worse total oral diet achievement.

CONCLUSION

Swallowing dysfunction represents a significant morbidity following glossectomy in the treatment of SCC. High BMI, smaller resection fields, and absence of prior radiation therapy or adjuvant chemoradiotherapy correlated with improved likelihood of obtaining a total oral diet. Patients should be appropriately counseled of this risk with emphasis placed on aggressive swallow rehabilitation in the post- treatment setting.

Dietary fiber intake and head and neck cancer risk: A pooled analysis in the International Head and Neck Cancer Epidemiology consortium

The possible role of dietary fiber in the etiology of head neck cancers (HNCs) is unclear. We used individual-level pooled data from ten case-control studies (5959 cases and 12,248 controls) participating in the International Head and Neck Cancer Epidemiology (INHANCE) consortium, to examine the association between fiber intake and cancer of the oral cavity/pharynx and larynx. Odds Ratios (ORs) and their 95% Confidence Intervals (CIs) were estimated using unconditional multiple logistic regression applied to quintile categories of non-alcohol energy-adjusted fiber intake and adjusted for tobacco and alcohol use and other known or putative confounders. Fiber intake was inversely associated with oral and pharyngeal cancer combined (OR for 5th vs. 1st quintile category = 0.49, 95% CI: 0.40-0.59; p for trend <0.001) and with laryngeal cancer (OR = 0.66, 95% CI: 0.54-0.82, p for trend <0.001). There was, however, appreciable heterogeneity of the estimated effect across studies for oral and pharyngeal cancer combined. Nonetheless, inverse associations were consistently observed for the subsites of oral and pharyngeal cancers and within most strata of the considered covariates, for both cancer sites. Our findings from a multicenter large-scale pooled analysis suggest that, although in the presence of between-study heterogeneity, a greater intake of fiber may lower HNC risk.

Black raspberries demethylate Sfrp4, a WNT pathway antagonist, in rat esophageal squamous cell papilloma

Aberrant methylation of DNA is a common event in the development of cancers, including squamous cell carcinoma (SCC) of the human esophagus. In the present study, we determined: (a) whether aberrant DNA methylation also occurs in the development of N-nitrosomethylbenzylamine (NMBA)-induced tumorigenesis in the rat esophagus, a model of human esophageal SCC; and (b) if so, whether dietary black raspberries (BRBs) are capable of preventing this aberrant DNA methylation. A diet containing 5% BRBs inhibited the development of NMBA-induced tumors in the rat esophagus. This inhibition was associated with reduced mRNA levels of the DNA methyltransferases, Dnmt1 and Dnmt3b, in both dysplastic lesions and in papillomas of the esophagus. In addition, promoter methylation of Sfrp4, a WNT pathway antagonist, was significantly reduced by the berry diet, and this was associated with decreased nuclear localization of β-CATENIN and reduced expression of c-MYC protein in NMBA-treated esophagi. Decreased promoter methylation of Sfrp4 correlated with decreased expression of Dmnt3b and, ultimately, with increased Sfrp4 mRNA expression. This suggests that epigenetic alterations in NMBA-induced rat esophageal tumorigenesis recapitulate epigenetic events in human esophageal SCC, and that BRBs could be useful in preventing the aberrant DNA methylation involved in the development of human esophageal SCC. © 2015 Wiley Periodicals, Inc.

Citrus consumption and risk of basal cell carcinoma and squamous cell carcinoma of the skin

Animal experiments have demonstrated the photocarcinogenic properties of furocoumarins, a group of naturally occurring chemicals that are rich in citrus products. We conducted a prospective study for citrus consumption and risk of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin based on data from 41530 men in the Health Professionals Follow-up Study (1986-2010) and 63759 women in the Nurses' Health Study (1984-2010) who were free of cancers at baseline. Over 24-26 years of follow-up, we documented 20840 incident BCCs and 3544 incident SCCs. Compared to those who consumed citrus products less than twice per week, the pooled multivariable-adjusted hazard ratios were 1.03 [95% confidence interval (95% CI): 0.99-1.08] for BCC and 1.14 (95% CI: 1.00-1.30) for SCC for those who consumed two to four times per week, 1.06 (95% CI: 1.01-1.11) for BCC and 1.15 (95% CI: 1.02-1.28) for SCC for five to six times per week, 1.11 (95% CI: 1.06-1.16) for BCC and 1.22 (95% CI: 1.08-1.37) for SCC for once to 1.4 times per day and 1.16 (95% CI: 1.09-1.23) for BCC and 1.21 (95% Cl: 1.06-1.38) for SCC for 1.5 times per day or more (P trend = 0.001 for BCC and 0.04 for SCC). In contrast, consumption of non-citrus fruit and juice appeared to be inversely associated with risk of BCC and SCC. Our findings support positive associations between citrus consumption and risk of cutaneous BCC and SCC in two cohorts of men and women, and call for further investigations to better understand the potential photocarcinogenesis associated with dietary intakes.

Dietary glucosylceramides suppress tumor growth in a mouse xenograft model of head and neck squamous cell carcinoma by the inhibition of angiogenesis through an increase in ceramide

BACKGROUND

We previously reported that dietary glucosylceramides show cancer-prevention activity in a mouse xenograft model of human head and neck cancer cells (SCCKN). However, the mechanism was unclear. Ceramides, metabolites of glucosylceramides, induce apoptotic cell death in various malignancies. Here, we investigated the inhibitory effects of dietary glucosylceramides on tumor growth in vivo and in vitro.

METHODS

SCCKN were subcutaneously inoculated into the right flanks of NOD/SCID mice. Mice were treated with or without dietary glucosylceramides (300 mg/kg) daily for 14 consecutive days after confirmation of tumor progression. Microvessel areas around the tumor were assessed by hematoxylin-eosin staining and immunohistochemistry of CD31, and, as markers for angiogenesis, protein levels of VEGF, VEGF receptor-2, and HIF-1α were assessed by Western blotting. Mass spectrometry was performed to measure the levels of sphingolipids in mouse serum after treatment with dietary glucosylceramides.

RESULTS

Oral administration of glucosylceramides significantly decreased SCCKN growth in the xenograft model with inhibition of angioinvasion. In tumor-invasive areas, VEGF and HIF-1α in the tumor cells, and VEGF receptor-2 in endothelial cells decreased after treatment with dietary glucosylceramides. Dietary glucosylceramides increased serum levels of sphingosine-based ceramides as compared to the control. In SCCKN and UV♀2 cells, C6-ceramide suppressed the expressions of VEGF, VEGF receptor-2, and HIF-1α in vitro.

CONCLUSION

These results suggest that dietary glucosylceramides trigger the de novo pathway of ceramide synthesis, indicating that sphingosine-based ceramide suppresses the growth of head and neck tumors through the inhibition of pro-angiogenic signals such as VEGF, VEGF receptor-2, and HIF-1α.

Feasibility and efficacy of progressive resistance training and dietary supplements in radiotherapy treated head and neck cancer patients--the DAHANCA 25A study

BACKGROUND

Patients with head and neck squamous cell carcinoma (HNSCC) often lose a considerable amount of muscle mass following the disease and treatment. This is an independent mortality predictor, lowering muscle strength and functional performance. Progressive resistance training (PRT) increases muscle mass among healthy individuals and groups of cancer patients, but it has not been investigated in HNSCC patients. Furthermore, studies in healthy subjects show an additive effect of protein and creatine supplementation following PRT.

OBJECTIVES

Firstly, to investigate the feasibility of 12 weeks of PRT ± protein and creatine supplementation among HNSCC patients. Secondly, to investigate group changes over time and group differences regarding lean body mass (LBM), muscle strength and functional performance following PRT ± dietary supplementation.

MATERIAL AND METHODS

Thirty patients were randomized into two groups: a PROCR group undergoing a seven-day pre-trial creatine loading protocol followed by 12 weeks of PRT with creatine and protein supplementation and a PLA group undergoing a seven-day pre-trial placebo ingestion protocol followed by an identical PRT protocol with placebo supplementation. Before the pre-trial and pre- and post-PRT evaluation of LBM, maximal isometric and isokinetic muscle strength and functional performance were performed.

RESULTS

Seventy percent of the patients completed the intervention and the PRT adherence rate was 97%. No significant group differences were found in any endpoints. From pre- to post-PRT, LBM increased significantly in the PROCR group by 2.6 ± 2.2 kg (p < 0.0001) and increased in the PLA group (1.3 ± 1.1 kg, p = 0.07). Maximal isometric and isokinetic muscle strength as well as functional performance increased significantly in both groups.

CONCLUSION

PRT is feasible in radiotherapy treated HNSCC patients. Following PRT, lean body mass, muscle strength and functional performance increased significantly in both groups (LBM only borderline significant in PLA group) with no significant group difference in any endpoint.

Soy protein extract (SPE) exhibits differential in vitro cell proliferation effects in oral cancer and normal cell lines

Prior research has demonstrated that specific isoflavones derived from soy may exhibit antitumor effects against many cancers, including oral cancer. Most of this prior research involved isolation and testing of individual soy components, such as genistein, daidzein, and glycitein, which exhibit cytotoxicity against cancerous cells but may also have residual cytotoxic effects on normal cells. Few studies have evaluated whole soy extract, containing a combination of these isoflavones, and other bioreactive compounds, which may function synergistically and more effectively against oral cancers. This study compared the antiproliferative effects of whole soy protein extract (SPE) on CAL 27 and SCC25 oral cancer cell lines in vitro. Administration of SPE significantly inhibited oral cancer growth and exerted these effects at lower concentrations compared with another class of flavonoids (proanthocyanidins) that were previously tested on these cell lines. This SPE-induced growth inhibition correlated with down-regulated mRNA expression in the oral cancer cell-cycle promoter ornithine decarboxylase (ODC), as well as upregulation of caspase-2 and caspase-8, initiators and effectors of apoptosis. These results suggest that SPE may represent a potential chemopreventive or chemotherapeutic option for oral cancer. Moreover, SPE may be more effective than other flavonoids currently used and may be effective at lower concentrations that approximate physiologic serum levels (0-2 μmol/l). This study may help to explain why diets rich in fruits, vegetables, and soy protein are associated with protection against development and progression of oral cancers, although further study is needed to develop specific public health recommendations for oral cancer treatment and prevention.

[Natural compounds in chemoprevention of esophageal squamous cell tumors--experimental studies]

Chemoprevention refers to prevention of tumor formation due to administration of nontoxic synthetic or natural compounds, which can block or weaken the influence of carcinogens on target cells or even reverse previously formed lesions. In esophageal squamous cell carcinoma--which belongs to the group of the most aggressive tumors of digestive system with poor prognosis--an effective prevention would be strongly expected. Chemopreventive properties of many complex diets and pure natural compounds were evaluated until now. Most studies were performed on rats exposed to chemical carcinogens, usually N-nitroso-N-methylbenzylamine (NMBA). The best effects were achieved after administration of diallyl sulfide and phenethyl isothiocyanate. Lyophilized black raspberries, blackberries and strawberries, as well as products obtained from leaves and buds of tea plant, elagic acid and resveratrol were also very effective. Mechanisms of chemopreventive action were associated with, i.e., activity of enzymes involved in carcinogen metabolic activation (mostly cytochrome P450 isoenzymes), inhibition of DNA adducts formation and modulation of gene expression involved in regulation of proliferation, apoptosis and angiogenesis. However, some agents e.g., perillyl alcohol, could enhance development of proliferative lesions in esophageal epithelium.

Prevention and therapy of squamous cell carcinoma of the rodent esophagus using freeze-dried black raspberries

AIM

This study was conducted to determine if short-term treatment of Nnitrosomethylbenzylamine (NMBA)-induced tumors in the rat esophagus with dietary freeze-dried black raspberries (FBR) would result in tumor regression and enhanced survival of the animals.

METHODS

Four-week-old male Fisher-344 rats were administered an AIN-76A control diet and injected subcutaneously with 0.5 mg/kg NMBA once per week for 15 weeks. At 19 weeks, when rats had an average of 5-6 tumors (papillomas) per esophagus, they were given a control diet containing either 5%, 10%, or 20% FBR. After 7 weeks of berry treatment, all surviving rats were killed and tumor incidence, number and volume were determined.

RESULTS

Esophageal tumor incidences, numbers and volumes in NMBA-treated rats were not influenced by any of the berry treatments. There were progressive increases in the survival of NMBA-treated rats fed 5%-20% FBR diets; however, these increases were not significant.

CONCLUSION

FBR at 5%, 10%, and 20% of the diet had no effect on the development of NMBA-induced tumors in the rat esophagus or on animal survival when administered for 7 weeks beginning at the papilloma stage of tumor development. Thus, FBR appear to have no therapeutic value in the treatment of esophageal tumors. In contrast, dietary FBR are highly effective in preventing the development of NMBA-induced esophageal tumors in rats when administered before and during NMBA treatment or shortly after NMBA treatment when the esophagi contain preneoplastic (dysplastic) lesions of varying degrees of severity.

Topical and light-based treatments for actinic keratoses

Actinic keratosis is currently believed to be an early stage in the evolution of squamous cell carcinoma. Active and intensive treatment of actinic keratosis may prevent the formation of invasive squamous cell carcinoma and potential metastases. While destructive methods of treatment of actinic keratosis remain the gold standard for the eradication of visible and palpable actinic keratoses, new medical therapies may accomplish this goal more comfortably and reliably for the patient. Newer topical medications, light therapy and photodynamic therapy are generating promising results that presage more widespread use in the future. These novel therapies for the early treatment of actinic keratosis may be administered in combination or serially, with the locus of treatment at any given time possibly restricted to a region of affected skin. Treatment of incipient or subclinical lesions may mitigate the risk of future squamous cell carcinomas lesions. Widespread actinic keratosis constitutes a persistent medical problem that requires long-term management. The role of traditional and novel treatments in the routine treatment of actinic keratosis will be determined by the efficacy, limitations and the practicality of each of these methods in individual patients. As the first stage of squamous cell carcinoma, actinic keratosis is worthy of prompt evaluation and active treatment.

Dangerous nutrition? Calcium, vitamin D, and shark cartilage nutritional supplements and cancer-related hypercalcemia

The use of nutritional supplements in the general population and in cancer patients has become very popular. These supplements are not perceived as medications and are presumed to be safe by cancer patients, who may however be at risk for hypercalcemia. We note that many of our patients who have developed symptomatic hypercalcemia were taking vitamin D, calcium, or shark cartilage supplements. We report eight cases of hypercalcemia in cancer patients seen at the Cleveland Clinic Foundation in whom these nutritional supplements may have contributed to the prevalence or severity of hypercalcemia.

Nutrition and head and neck cancer

The role of nutrition in patients with head and neck cancer, specifically squamous cell carcinoma, is underappreciated. The composition of the diet can contribute to carcinogenesis, and specific nutrients may offer some protection in the presence of known carcinogens (ie, tobacco). Patients with head and neck cancer are frequently malnourished, which may have prognostic implications for the morbidity and outcome of therapies. Although the benefits of preoperative nutritional supplementation have been demonstrated only in severely malnourished patients, the use of immune-enhancing formulas may prove to be beneficial. Special consideration should be given to the nutritional needs and possible interactions of diet and therapy in patients receiving radiation and chemotherapy. Physicians should be cognizant of the widespread use of alternative diets and nutritional supplements that can be harmful and may interact with standard treatments. New knowledge regarding the role of nutrition in cancer offers hope for the nutritional chemoprevention of head and neck cancers.

Tomatoes, tomato-rich foods, lycopene and cancer of the upper aerodigestive tract: a case-control in Uruguay

In order to study the relationship between tomatoes, tomato products, lycopene and cancers of the upper aerodigestive tract (UADC; oral cavity, pharynx, larynx, esophagus) a case-control study was carried out in Uruguay, in the time period 1996-98. Two-hundred and thirty eight cases and 491 hospitalized controls were frequency matched on age, sex, residence and urban/rural status. Both series were submitted to a detailed questionnaire, including tobacco smoking, alcohol drinking and queries on 64 food items. These data were analyzed by unconditional logistic regression, after adjusting by total energy intake. Tomato intake was associated with a reduction in risk of 0.30 (95% confidence interval [CI], 0.18-0.51), whereas tomato sauce-rich foods displayed a protective effect of 0.57 (95% CI, 0.33-0.96 for the highest quartile of intake). The food group composed of raw tomato and tomato-rich foods showed a strong inverse association with UADC (odds ratio [OR], 0.23; 95% CI, 0.13-0.39 for the highest quartile of intake). Lycopene was also strongly associated with a reduced risk of 0.22 (95% CI, 0.13-0.37). Adjustment of tomato intake for several phytochemicals explained almost completely its protective effect, which disappears in this model. Finally, the joint effect of lycopene and total phytosterols was associated with a significant reduction in risk (OR, 0.11; 95% CI, 0.05-0.23).

Decreased incidence of prostate cancer with selenium supplementation: results of a double-blind cancer prevention trial

OBJECTIVE

To test if supplemental dietary selenium is associated with changes in the incidence of prostate cancer.

PATIENTS AND METHOD

A total of 974 men with a history of either a basal cell or squamous cell carcinoma were randomized to either a daily supplement of 200 microg of selenium or a placebo. Patients were treated for a mean of 4.5 years and followed for a mean of 6.5 years.

RESULTS

Selenium treatment was associated with a significant (63%) reduction in the secondary endpoint of prostate cancer incidence during 1983-93. There were 13 prostate cancer cases in the selenium-treated group and 35 cases in the placebo group (relative risk, RR=0.37, P=0.002). Restricting the analysis to the 843 patients with initially normal levels of prostate-specific antigen (< or = 4 ng/mL), only four cases were diagnosed in the selenium-treated group and 16 cases were diagnosed in the placebo group after a 2 year treatment lag, (RR=0.26 P=0.009). There were significant health benefits also for the other secondary endpoints of total cancer mortality, and the incidence of total, lung and colorectal cancer. There was no significant change in incidence for the primary endpoints of basal and squamous cell carcinoma of the skin. In light of these results, the 'blinded' phase of this trial was stopped early.

CONCLUSIONS

Although selenium shows no protective effects against the primary endpoint of squamous and basal cell carcinomas of the skin, the selenium-treated group had substantial reductions in the incidence of prostate cancer, and total cancer incidence and mortality that demand further evaluation in well-controlled prevention trials.

Effect of a low-fat diet on the incidence of actinic keratosis

BACKGROUND

Actinic keratoses are premalignant lesions and are a sensitive and important manifestation of sun-induced skin damage. Studies in animals have shown that dietary fat influences the incidence of sun-induced skin cancer, but the effect of diet on the incidence of actinic keratosis in humans is not known.

METHODS

We randomly assigned 76 patients with nonmelanoma skin cancer either to continue their usual diet (control group) or to eat a diet with 20 percent of total caloric intake as fat (dietary-intervention group). For 24 months, the patients were examined for the presence of new actinic keratoses by physicians unaware of their assigned diets.

RESULTS

At base line, the mean (+/- SD) percentage of caloric intake as fat was 40 +/- 4 percent in the control group and 39 +/- 3 percent in the dietary-intervention group. After 4 months of dietary therapy the percentage of calories as fat had decreased to 21 percent in the dietary-intervention group, and it remained below this level throughout the 24-month study period. The percentage of calories as fat in the control group did not fall below 36 percent at any time. The cumulative number of new actinic keratoses per patient from months 4 through 24 was 10 +/- 13 in the control group and 3 +/- 7 in the dietary-intervention group (P = 0.001).

CONCLUSIONS

In patients with a history of nonmelanoma skin cancer, a low-fat diet reduces the incidence of actinic keratosis.

Esophageal morphology from Linxian, China. Squamous histologic findings in 754 patients

BACKGROUND

Linxian, China, has one of the highest rates of esophageal cancer in the world. Other authors have described high prevalences of histologic esophagitis, atrophy, and dysplasia in Linxian and have suggested that these findings may represent precancerous lesions in this population. In 1987, a new endoscopic survey allowed the authors to make an independent study of esophageal histology in Linxian.

METHODS

There were 1567 satisfactory squamous esophageal biopsies available from 754 patients. These biopsies were classified as normal, atrophy, acanthosis, esophagitis, squamous dysplasia, or squamous cancer.

RESULTS

Classified by their worst diagnosis, 56.5% of the 754 patients had normal mucosa, 0.0% atrophy, 11.5% acanthosis, 4.6% esophagitis, 22.7% squamous dysplasia, and 4.6% squamous cancer.

CONCLUSIONS

The results show a different distribution of esophageal squamous diagnoses than has been reported previously from this population. The authors believe that the major reason for this discrepancy was differences in histologic criteria. In this survey, seemingly small differences in criteria could cause large differences in apparent disease prevalence; this was especially true for esophagitis. By the criteria used in this study, histologic esophagitis and atrophy are uncommon findings in Linxian, raising questions about their significance as precursor lesions of esophageal cancer in this population.

A pilot study on the use of plasma carotenoids and ascorbic acid as markers of compliance to a high fruit and vegetable dietary intervention

The authors examined the feasibility of using plasma carotenoids and ascorbic acid as markers of compliance for dietary intervention trials aimed at increasing the quantity and variety of the fruit and vegetable intake of free-living individuals. Nineteen former cancer patients who had been successfully treated for a stage I or II squamous cell carcinoma of the mouth, pharynx, larynx, or lung were recruited. Subjects served as their own controls. However, in order to detect any seasonal trends, 4 individuals among the 19 were randomized to a nonintervention group. Subjects in the intervention group were counseled by dietitians with the goal of increasing their intake of fruits and vegetables to eight servings/day (1 serving each of dark green vegetables, yellow-orange vegetables, tomato products, and other vegetables; 3 servings of vitamin C-rich fruits; and 1 serving of other fruits). Subjects in the nonintervention group were advised to follow their usual diet. Three-day measured food records kept at base line and after 3 months of intervention, as well as unannounced 24-h dietary recalls, documented an increase in mean fruit and vegetable intake from 4.2 to 9.5 servings daily in the intervention group. A concomitant increase of 29% was observed in total plasma carotenoids (P = 0.02), with increases of 25% for plasma lycopene (P = 0.06), 31% for plasma lutein (P = 0.002), 39% for plasma beta-carotene (P = 0.01), and 57% for plasma alpha-carotene (P = 0.01). Mean plasma levels of ascorbic acid increased by 27% (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Oral and pharyngeal cancer, diet, smoking, alcohol, and serum vitamin A and beta-carotene levels: a case-control study in men

A case-control study was conducted in Melbourne, Australia. Forty-one men with histologically confirmed squamous cell oral or pharyngeal cancer were compared with 398 male community controls. A statistically significant increase in risk was found for alcohol (ethanol) consumption and for smoking, and there was a synergistic effect for these two exposures. Statistically significant protection was noted with increasing intake of dietary vitamin C, dietary beta-carotene, fruit, vegetables, and dietary fiber. The mean serum levels of beta-carotene and vitamin A were statistically significantly lower when the cases were compared with another set of 88 male controls of a similar age who were hospitalized for minor surgical operations. This study confirms a causal effect of smoking and alcohol and a protective role for a high dietary intake of fruit, vegetables, cereals, and, particularly, beta-carotene- and vitamin C-containing foods.

Pulmonary reaction to an aspirated balanced liquid diet in a cancer patient

A 60-year-old man with pharyngeal carcinoma developed spontaneous pneumothorax. A biopsied lung tissue revealed an extensive granulomatous reaction to some yellow material. Because of the patient's frequent aspirations of the liquid diet which was mixed with an artificial lemon flavor, it is considered that the aspirated material provoked the pulmonary reaction and possibly the pneumothorax. An energy dispersive X-ray analysis of the biopsied lung tissue aided in excluding the possibility of the pulmonary reaction and the yellow material being of ubiquitous pneumoconiotic origin.

Whole-body protein metabolism in cancer-bearing patients. Effect of total parenteral nutrition and associated serum insulin response

Aggressive nutritional support of the cancer patient undergoing treatment has become widespread standard practice. In order to evaluate the effect of total parenteral nutrition (TPN) on protein metabolism, 11 patients with localized squamous cell carcinoma of the distal esophagus were studied in the postabsorptive state and again after 2 weeks of TPN. After two weeks of TPN, these cancer patients demonstrated a significant increase in body weight associated with positive nitrogen balance and an insignificant increase in total body potassium (determined by whole body 40K scanning), a measure of lean body mass. Serum transferrin, ceruloplasmin, and total protein did not change significantly, whereas serum albumin decreased significantly (3.5 +/- 0.1 to 3.1 +/- 0.1 g dl-1). Evaluation of whole-body protein kinetics by constant infusion of 15N-glycine demonstrated a significant increase in protein flux (2.79 +/- 0.20 to 4.02 +/- 0.33 g protein kg-1 day-1). In the group as a whole, protein synthesis increased and catabolism decreased, but not significantly. Skeletal muscle protein catabolism, as measured by the rate of excretion of urinary 3-methylhistidine (mumol kg-1 day-1) decreased significantly after 2 weeks of TPN (2.5 +/- 0.1 to 1.9 +/- 0.2). A change from basal to stimulated (TPN) serum insulin level of 40 to 120 microU/ml was found to be associated with optimal changes in protein synthesis and skeletal muscle catabolism. Five patients fell within this optimal range of serum insulin, and demonstrated a significant increase in the rate of wholebody protein synthesis (2.13 +/- 0.35 to 3.56 +/- 0.45 g protein kg-1 day-1) with an insignificant increase in whole-body protein catabolism (2.74 +/- 0.42 to 3.16 +/- 0.43), and a significant decrease in urinary 3-methylhistidine excretion (2.50 +/- 0.35 to 1.53 +/- 0.24) after 2 weeks of TPN. It is concluded that optimum nutritional support with TPN is beneficial to the cancer patients' protein economy by stimulating whole body protein synthesis while decreasing skeletal muscle protein catabolism. It is also concluded that there exists a range of serum insulin in which whole-body protein synthesis and catabolism are optimized.

Calorie restriction: effect on growth of human tumors heterotransplanted in nude mice

The presence of 4 human malignant tumors (1 breast, 1 lung, and 2 colon carcinomas) growing subcutaneously as heterotransplants in nude mice did not significantly affect the body weights of adult animals until the tumors reached very large dimensions (tumor wt greater than 15% of the body wt). However, a colon carcinoma (HT 29) induced a cessation of the natural rate of body weight increase when it grew in young adults (animals weighing approximately equal to 25 g which will gain 6 g or approximately equal to 25% body wt in 1 mo). Calorie restriction at all the levels tested (8, 6, 4, and 2 g/day/mouse) with standard pelletized mouse food produced both weight loss in the animals (with and without tumor) and a lowering of the growth rate of all the 4 tumors tested growing at a subcutaneous site and/or under the kidney capsule. Each tumor responded differently to the calorie restriction. The 4 tumors tested grew equally in both male and female nude mice. Young animals weighing 20 g inoculated with a fifth tumor (MeWo melanoma) exhibited tumor growth inhibition proportional to restriction of calorie intake. Their survival, however, did not improve.

Intravenous hyperalimentation as an adjunct to colon interposition for carcinoma of the esophagus

Ten consecutive malnourished patients with undifferentiated squamous cell carcinoma of the esophagus underwent operation for colon interposition. They received intravenous hyperalimentation preoperatively and/or postoperatively for an average time of 21.5 days and had an average weight gain of 6.5 lb. There was no significant gastrointestinal morbidity, but one patient succumbed to aspiration pneumonia. All ten patients had postoperative gastrografin swallow radiography which showed no leaks in either anastomosis. With proper use of intravenous hyperalimentation, morbidity and mortality following colon interposition in the malnourished patient for either palliative or curative bypass can be decreased to acceptable levels.