Impact of mandated drug monitoring on opioid use during highly conformal radiotherapy for oropharynx cancer

BACKGROUND

Prescription drug monitoring programs (PDMPs) have proliferated due to increasing opioid-related deaths. We evaluated acute opioid use changes for 64 patients treated with highly conformal radiotherapy (RT) following a state-mandated PDMP.

METHODS

Patients receiving proton therapy (PT) (n=40), intensity-modulated RT (IMRT) (n=14), or both (n=10) were divided into preintervention (n=26) and postintervention cohorts (n=38); records were reviewed retrospectively under an institutional review board (IRB)-approved tracking protocol. Dosages prescribed during acute therapy (during RT-3 months post-RT) and patient-reported pain (Defense and Veterans Pain Rating Scale) were endpoints. Dosages were treated as responses in Chi-square tests (three-level ordinal response).

RESULTS

Overall, 72% (n=46) received opioids; of which 22% (n=10) of all patients and 10% (n=2) of opioid-naive patients continued analgesic management 3 months post-RT. Median total doses were 975 and 1,025 morphine milligram equivalents (MME) in pre- and postintervention groups, with no significant differences in MME prescribed (P=0.8) or uncontrolled pain (P=0.3). Statistically significant factors were tonsil primaries (P<0.01) and alcohol use (P=0.02). Uncontrolled pain episodes during and post-RT did not vary per cohort (P=0.19).

CONCLUSIONS

PDMP use was not associated with management changes in patient-reported acute pain during RT (IMRT or PT). Following highly conformal RT, few patients remained on narcotics 3 months post-RT.

CD8 infiltration is associated with disease control and tobacco exposure in intermediate-risk oropharyngeal cancer

Oropharyngeal squamous cell carcinoma (OPSCC) incidence is increasing at a nearly epidemic rate, largely driven by the human papillomavirus (HPV). Despite the generally favorable clinical outcomes of patients with HPV driven (HPV+) OPSCC, a significant subset of HPV tumors associated with tobacco exposure have diminished treatment response and worse survival. The tumor immune microenvironment (TIME) has been shown to be a critical driver of treatment response and oncologic outcomes in OPSCC generally and HPV+ OPSCC more specifically. However, the impact of tobacco exposure on the TIME in OPSCC patients remains unclear. We analyzed the relationship between TIME, tobacco exposure and clinical outcomes in OPSCC patients (n = 143) with extensive tobacco exposure (median pack-years = 40). P16 overexpression, a surrogate marker of HPV association, was a strong predictor of relapse-free (RFS) and overall survival (OS) (p < 0.001, p < 0.001 respectively) regardless of tobacco exposure and associated strongly with differential infiltration of the tumor by both CD3 and CD8 lymphocytes measured via immunohistochemistry (p < 001, p < 0.001 respectively). CD3 and CD8 infiltration was a strong predictor of RFS and OS and associated strongly with disease stage (AJCC 8th Edition Staging Manual). Tobacco exposure correlated significantly (p < 0.001) with decreased CD8 infiltration in p16+ OPSCC tumors. Our findings demonstrate that the HPV+ OPSCC clinical outcomes are strongly correlated with the TIME, which is potentially modulated by tobacco exposure. Immunomodulatory strategies targeting this disease in smokers must take into consideration the potential modifying effects of tobacco exposure on treatment effectiveness and clinical outcomes.

Could the endocrine disruptor bisphenol-A be implicated in the pathogenesis of oral and oropharyngeal cancer? Metabolic considerations and future directions

Bisphenol-A (BPA), a prototype endocrine disrupting molecule, has been associated with many disease entities such as diabetes mellitus, obesity, polycystic ovarian disease, cardiovascular disease, reproductive and neurodevelopmental disorders. BPA has also been associated mainly with not only hormone sensitive cancers such as breast, prostate, endometrial, ovarian, testicular and thyroid cancers but also non-hormonal sensitive cancers such as cervical and lung cancers, osteosarcoma and meningioma. Recent research has investigated the sources of contamination which are responsible for higher BPA concentrations in the oral cavity and oropharyngeal space, representing the first site of BPA exposure after ingestion. Besides growing awareness and case registration, the incidence and prevalence of oral (OC) and oropharyngeal cancer (OPC) have increased during the last decades correlating with the increased production of BPA worldwide. So far, no study in the medical literature has explored the association of BPA with OC and OPC. BPA may be linked to the etiopathogenesis of OC and OPC through a multitude of mechanisms encompassing and interconnecting genetic, epigenetic, inflammatory, immune, metabolic, hormonal and oxidative stress alterations as well as modulation of oral microbiome. Hence, it is not possible to rule out a potential role of BPA exposure in oral and oropharyngeal tissue carcinogenesis, especially knowing its potential to participate in other non-hormonal sensitive malignancies and to deregulate signaling pathways implicated in OC and OPC. This perspective aims at outlining evidence and proposing for the first time a potential link between BPA with OC and OPC, the most frequent subtypes of head and neck malignancies.

mTOR inhibition prevents rapid-onset of carcinogen-induced malignancies in a novel inducible HPV-16 E6/E7 mouse model

The rising incidence of human papillomavirus (HPV)-associated malignancies, especially for oropharyngeal cancers, has highlighted the urgent need to understand how the interplay between high-risk HPV oncogenes and carcinogenic exposure results in squamous cell carcinoma (SCC) development. Here, we describe an inducible mouse model expressing high risk HPV-16 E6/E7 oncoproteins in adults, bypassing the impact of these viral genes during development. HPV-16 E6/E7 genes were targeted to the basal squamous epithelia in transgenic mice using a doxycycline inducible cytokeratin 5 promoter (cK5-rtTA) system. After doxycycline induction, both E6 and E7 were highly expressed, resulting in rapid epidermal hyperplasia with a remarkable expansion of the proliferative cell compartment to the suprabasal layers. Surprisingly, in spite of the massive growth of epithelial cells and their stem cell progenitors, HPV-E6/E7 expression was not sufficient to trigger mTOR activation, a key oncogenic driver in HPV-associated malignancies, and malignant progression to SCC. However, these mice develop SCC rapidly after a single exposure to a skin carcinogen, DMBA, which was increased by the prolonged exposure to a tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). Thus, only few oncogenic hits may be sufficient to induce cancer in E6/E7 expressing cells. All HPV-E6/E7 expressing SCC lesions exhibited increased mTOR activation. Remarkably, rapamycin, an mTOR inhibitor, abolished tumor development when administered to HPV-E6/E7 mice prior to DMBA exposure. Our findings revealed that mTOR inhibition protects HPV-E6/E7 expressing tissues form SCC development upon carcinogen exposure, thus supporting the potential clinical use of mTOR inhibitors as a molecular targeted approach for prevention of HPV-associated malignancies.

Mouthwash and oral cancer risk quantitative meta-analysis of epidemiologic studies

BACKGROUND

Use of mouthwash and an increased risk of oral cancer has been a source of controversy for decades. A meta-analysis of epidemiological studies of mouthwash and oral cancer and, specifically, mouthwash containing >25% alcohol, was undertaken.

METHODS

Summary estimates were obtained with maximum likelihood estimates from random effects models. Sensitivity analyses were conducted to evaluate the influence of various inclusion.

RESULTS

Eighteen studies were included in the meta-analysis. There was no statistically significant associations found between regular use of mouthwash and risk of oral cancer (RR=1.13; 95% CI (0.95-1.35)). There was no significant trend in risk of oral cancer associated with increased daily usage of mouthwash (p=0.11). There was no association between reported use of mouthwash specifically containing alcohol and risk of oral cancer (RR=1.16; 95% CI (0.44, 3.08)).

CONCLUSIONS

This quantitative analysis of mouthwash use and oral malignancy revealed no statistically significant associations between mouthwash use and risk of oral cancer, nor any significant trend in risk with increasing daily use; and no association between use of mouthwash containing alcohol and oral cancer risk.

Chromosomal alterations and mutagen sensitivity in human mucosal cells of the oropharynx and lymphocytes caused by BPDE

BACKGROUND

In addition to exogenous risk factors, the development of head and neck cancer is based on genetic alterations and individual mutagen sensitivity. DNA damage caused by xenobiotics is not uniformly distributed over the DNA, as certain chromosomes and genes are more likely to be damaged than others. The DNA damaging effect of xenobiotics and the specific sites of chromosomal changes require further investigation.

MATERIALS AND METHODS

In order to evaluate mutagen sensitivity in macroscopically healthy mucosal tissue of 30 patients with (15) and without cancer (15) of the oropharynx, three different chromosomes (chromosomes 3, 5 and 8) involved in carcinogenesis of the oropharynx and one control chromosome (chromosome 1) were examined. After incubation with benz[a]pyren-7,8-diol-9,10-epoxide (BPDE), a tobacco-associated carcinogen, comet fluorescence in situ hybridization (FISH) was applied to assess DNA damage of these chromosomes. Furthermore, lymphocytes and macroscopically healthy mucosal cells of the oropharynx were assessed using FISH after their incubation with BPDE in order to evaluate loss and gain of DNA in these chromosomes.

RESULTS

BPDE caused significant DNA damage compared to the negative control in oropharyngeal mucosa cells of patients with and without carcinoma. No difference was observed between mutagen sensitivity of patients suffering from cancer of the oropharynx and patients without malignancy. In cells from patients suffering from squamous cell carcinoma, significantly higher DNA damage was found in chromosome 5 and 8 after incubation with BPDE and application of comet FISH. No difference was found in patients without cancer of the head and neck. After application of FISH, no difference in the amount of DNA was found in chromosomes 1, 3, 5 and 8, neither in lymphocytes nor in mucosal cells from both groups. No DNA gain or loss was detected.

CONCLUSION

Our results confirm the higher sensitivity of chromosomes 5 and 8 of normal epithelial cells of oropharyngeal cancer patients to BPDE. These effects were shown in macroscopically healthy tissue of such patients for the first time. Therefore, we suggest that these are early onset effects in carcinogenesis of the head and neck. No such effect was shown for chromosome 3 and control chromosome 1.

Alcohol-containing mouthwash and oropharyngeal cancer: a review of the epidemiology

BACKGROUND

There has been concern that the use of alcohol-containing mouthwash may increase the risk of developing oropharyngeal cancer, or OPC. The authors examine the epidemiologic literature relating to this issue.

TYPES OF STUDIES REVIEWED

The authors identified all nine English-language epidemiologic studies of OPC that made reference to mouthwash. The findings and major strengths and limitations of each study are described. In addition, the authors reanalyzed data from one of the studies.

RESULTS

The results of six of the studies reviewed are negative and provide no support for the hypothesis that use of alcohol-containing mouthwash increases the risk of OPC. One of the three studies with positive results was a case series and included a follow-up case-control study, the results of which were negative. The authors reanalyzed the study with the most positive results. This analysis found that the study results were just as positive for nonmucosal cancers developing in the mouth as they were for the usual type of OPC. The authors concluded that this study's positive finding resulted from recall bias.

CLINICAL IMPLICATIONS

It is unlikely that the use of mouthwashes that contain alcohol increases the risk of developing OPC.

Altered genotoxicity in mucosal cells of head and neck cancer patients due to environmental pollutants

The complexity of carcinogenesis in squamous cell cancer (SCC) of the upper aerodigestive tract requires examining environmental risk factors, including mutagen sensitivities to xenobiotics. Three environmental, occupational, and habitual pollutants - dibutylphthalate (DBP), diisobutylphthalate (DiBP), and N'nitrosodiethylamine (NDELA) - were submitted to genotoxicity testing on mucosal biopsy specimens of tumor and nontumor patients in vitro. The single-cell microgel electrophoresis (Comet) assay was applied to detect DNA strand breaks in human epithelial cells of the pharynx and larynx from nontumor patients, patients with SCC of the oropharynx and patients with SCC of the larynx. Genotoxicity was found for DBP, DiBP, and NDELA in cells derived from nontumor and tumor patients. With respect to phthalates, Olive tail moment (OTM) levels were higher in patients with SCC of the oropharynx and SCC of the larynx (P < 0.01), the latter showing even more pronounced genotoxicity for DiBP. Testing epithelial cells of the patients with either oropharyngeal or laryngeal SCC for NDELA demonstrated results similar to the nontumor patients. Present findings indicate heterogeneous mutagen sensitivities to some but not all xenobiotics.

Placental glutathione S-transferase isoenzyme expression during promotion of two-stage hamster cheek-pouch carcinogenesis

Glutathione S-transferases (GSTs) are the products of a multigene family. A well-established function of GSTs is to metabolize carcinogens by catalysing the conjugation of electrophilic substrates to glutathione. Whether placental GST (GST-P) is expressed during the promotion of two-stage hamster buccal-pouch mucosa (HBPM) carcinogenesis was investigated here, using 7,12-dimethylbenz[a]anthracene (DMBA) as the initiator and 12-O-tetradecanoylphorbol-13-acetate (TPA) as the promoter. Cytoplasmic and nuclear staining for GST-P was seen in pouches treated with DMBA for 4 or 16 weeks, as well as in those treated with DMBA for 4 weeks and then TPA for 12 weeks. No GST-P positivity was seen in any pouches treated with only TPA or with mineral oil for either 4 or 16 weeks. The average number of GST-P-stained foci in the groups treated with DMBA for 16 weeks (246 +/- 96; mean +/- SD) or DMBA for 4 weeks followed by TPA for 12 weeks (186 +/- 67) was significantly higher than in pouches treated with only DMBA for 4 weeks (97 +/- 24). These results demonstrate that TPA alone is not sufficient for GST-P expression in hamster buccal pouch mucosa. However, after being initiated with DMBA, then promoted with TPA, GST-P activity is induced in hamster buccal pouch mucosa during squamous-cell carcinogenesis. This underpins the suggestion that GST-P may play an important part during the promotion stage of oral carcinogenesis.

Tobacco consumption practices and risk of oro-pharyngeal cancer: a case-control study in Central India

A hospital based, group matched case control study was conducted with the objective to assess the association between tobacco consumption practices and risk of development of oro-pharyngeal cancer in Central India. The study included 123 cases of oro-pharyngeal cancer, diagnosed on the basis of histopathology at three tertiary care centers in Nagpur city. Each case was matched for age and sex with two hospital controls: one selected from non-cancer patients and another from patients having cancer of other sites. Tobacco chewing (OR=7.98, 95% CI 4.11-13.58) and tobacco smoking (OR=2.25, 95% CI 1.22-3.70) were found to be significantly associated with oro-pharyngeal cancer on unconditional multiple logistic regression analysis. Further analysis revealed a dose-response relationship between increasing frequency, duration and retention time of tobacco in mouth and risk of oro-pharyngeal cancer. Other risk factors which were also found to contribute significantly in the outcome of oro-pharyngeal cancer in the study population were: use of traditional/local substances (eg pan, betel nut, lime) with or without tobacco, use of tobacco containing material for teeth cleaning, type of smoking (eg bidi, chillum, cigarette) and outdoor occupations. High values of estimates of attributable risk percent (ARP) and population attributable risk percent (PARP) confirmed the positive impact of reduction or elimination of the tobacco consumption practices on reducing the risk of oro-pharyngeal cancer in the population of Central India.

A qualitative and quantitative risk assessment of snuff dipping

The presence of highly carcinogenic tobacco-specific nitrosamines (TSNA) in snuff has been a matter of serious concern. However, the levels of TSNA in such products may differ by orders of magnitude depending on origin and manner of processing, and the mere presence of such agents at low levels does hardly constitute a meaningful prerequisite for classifying all types of snuff as human carcinogens. Reviewing available epidemiological evidence, a wide discrepancy is found for estimated cancer risk associated with snuff dipping derived from on one hand previous investigations conducted in the United States and on the other from recent extensive Swedish epidemiological studies. In spite of the fact that approximately 20% of all grown-up Swedish males use moist snuff, it has not been possible to detect any significant increase in the incidence of cancer of the oral cavity or pharynx-the prevalence of which by international standards remains low in this country. Further, there is insufficient evidence for a causal link between the use of Swedish snuff and increased risk for cardiovascular disease. Dissimilarities in the content of TSNA in oral snuff products may represent one important reason for the different outcomes of the epidemiological surveys conducted in the United States and Sweden. Bioassays using pure TSNA in rodents appear to give exaggerated risk estimates for humans, a discrepancy that could be ascribed to species-related differences in the relation between exposure and DNA target dose and/or adduct repair rates, as well as to the presence of anticarcinogens in snuff. Although a small risk cannot be excluded, the use of smokeless tobacco products low in TSNA which now are available on the market entails a risk that at any rate is more than 10 times lower than that associated with active smoking. Nevertheless, due to the decisive role of potent TSNA in determining possible cancer risks in users of smokeless tobacco, and due to the fact that large variations in the concentrations may occur, adequate control measures should be taken to keep the levels of these nitrosamines in smokeless tobacco products as low as is technically feasible.

[Occupational exposure to hazardous substances and risk of cancer in the area of the mouth cavity, oropharynx, hypopharynx and larynx. A case-control study]

A case-control study of squamous cell carcinoma of the upper aerodigestive tract conducted in Heidelberg and Giessen (FRG) provided information on occupational factors in 200 patients and 800 controls (adjusted to sex, age and area of living; 4:1 matched design). The number of subjects exposed to wood dusts, organic chemicals, coal products or to cement was significantly elevated in the tumour group. An increased risk for head and neck cancer was observed after exposition to wood dust (RR = 2,2), organic compounds (RR = 2,4), coal products (RR = 2,7) and especially to cement (RR = 4,4). The cancer risk due to cement exposition showed a positive correlation to the duration of exposition and remained significantly elevated after adjustment for alcohol and tobacco consumption.

Carcinogenicity of the isomeric, N-nitroso-delta3-and N-nitroso-delta2-piperidines in rats and the in vivo isomerization of the delta3-to the delta2-isomer

N-Nitroso-1,2,3,6-tetrahydropyridine (N-nitroso-delta3-piperidine), N-nitroso-1,2,3,4-tetrahydropyridine (N-nitroso-delta2-piperidine) and N-nitroso-3,4-epoxypiperidine were tested for carcinogenicity in Fischer 344 rats. The unsaturated nitrosamines were administered in drinking water (100 mg/l). The epoxide was administered by gavage in corn oil (11.5 mg/ml, 0.2 ml twice a week). Both of the unsaturated nitrosamines were potent carcinogens (most of the animals died by the 35th week), and both produced many esophageal tumors, a property which they have in common with the parent compound, N-nitrosopiperidine. The spectrum of the other tumors formed, however, was different. The delta3-isomer produced hemangioendothelial sarcomas in the liver, which were absent in the tumor spectrum of the delta2-isomer and N-nitrosopiperidine. The delta2-isomer, on the other hand, produced tumors of the forestomach and the oropharynx, which were essentially absent in the rats treated with the delta3-isomer. N-nitroso-3,4-epoxypiperidine was a toxic compound (8 deaths in the first 5 weeks), but most of the remaining animals survived to 40 weeks. Of these, 8 animals died of induced tumors (esophagus and liver). The delta2- and the delta3-isomers were administered by gavage to groups of rats and the blood of these animals was withdrawn at timed intervals. Analysis of the serum revealed that both of the nitrosamines were cleared rapidly from circulation but that at the same time the delta3-isomer was being isomerized to the delta2. The reverse transformation did not occur in vivo.