Trends in oral cancer mortality in Japan: 1950-1993

Trends in mortality rates for oral and oropharyngeal cancer in Spain, 1979-2018

OBJECTIVE

To analyse mortality rate trends in Spain for oral cavity and oropharyngeal cancer (OCOPC) from 1979 to 2018, evaluating differences between oral cavity cancer (OCC) and oropharyngeal cancer (OPC).

MATERIALS AND METHODS

Death certificates and mid-year population data were collected from the Spanish National Statistics Institute. Age-standardized mortality rates were calculated using the direct method. Joinpoint regressions were used to identify significant changes in mortality trends. Independent effects of age, period and cohort (APC) were estimated.

RESULTS

A total of 52,057 deaths were registered from OCOPC, 38,988 from OCC and 13,069 from OPC between 1979 and 2018. While OCC mortality rates declined, OCOPC rates increased slightly and OPC significantly. OCC and OPC mortality reached their highest values between 1979 and 1992, when OCC rates began to decrease in males and OPC levelled off until 2018. Lip cancer suffered the highest drop. APC models showed a mortality increase in males and females from 40 to 45 and 50 to 55 years of age, respectively.

CONCLUSIONS

Favourable OCC mortality trends was plausibly influenced by decreased tobacco/alcohol consumption, while OPC rise was probably associated with increased human papillomavirus infection. The importance of closely monitoring these cancers by age group, sex and location, and continuing with preventive measures against known risk factors, is highlighted.

Detection of serum/salivary exosomal Alix in patients with oral squamous cell carcinoma

OBJECTIVE

Owing to variations in the exterior appearances of noncancerous diseases in the oral cavity, clinicians may have difficulty diagnosing oral squamous cell carcinoma (OSCC). Tissue biopsy is confirmatory, but invasive. Therefore, reliable tumor markers for OSCC are required. Here, exosomal Alix (exoAlix) levels were measured in serum/salivary samples from patients with OSCC and healthy controls (HCs).

METHODS

Fifty-seven patients admitted to Nagoya University Hospital from 2017 through 2019 were enrolled, and serum samples (OSCC, n = 29; HC, n = 21) and/or saliva samples (OSCC, n = 23; HC, n = 20) were collected. Exosomal fractions were isolated using ultracentrifugation. ExoAlix levels were measured using enzyme-linked immunosorbent assay.

RESULTS

Serum/salivary exoAlix levels were significantly higher in patients with OSCC than in HCs. Receiver operating characteristic analyses revealed that sensitivity, specificity, positive predictive value, and area under the curve were 0.345, 1.000, 1.000, and 0.685, respectively, for serum exoAlix and 0.348, 1.000, 1.000, and 0.712, respectively, for salivary exoAlix at optimal cut-off values (serum, 0.205; saliva, 0.193). All tested OSCC tissue sections (n = 21) were immuno-reactive for Alix.

CONCLUSION

Serum and salivary exoAlix were identified as potential diagnostic OSCC biomarkers. Serum exoAlix was suitable for prediction of therapeutic responses.

198Au grain implantation for early tongue cancer in patients of advanced age or poor performance status

Brachytherapy using (198)Au grains is minimally invasive and the only curative treatment for early tongue cancer in patients of advanced age or poor performance status available in our institution. From March 1993 to February 2008, (198)Au grains were used to treat a group of 96 Stage I-II tongue cancer patients who could not undergo surgery or brachytherapy using (192)Ir pins because of an advanced age (≥75 years) or poor performance status (≥2). The patients were followed for 3.9 ± 3.3 years, and the cause-specific survival and local control rates were determined. Survival analyses were performed using the Kaplan-Meier method, and univariate and multivariate analyses were performed using the Cox proportional hazard model. The results were compared with those for a group of 193 early tongue-cancer patients who underwent treatment using iridium pins. The 5-year cause-specific survival and local control rates of the (198)Au grains group were 71% and 68%, respectively, both of which were 16% lower than the corresponding rates for the (192)Ir pins group. Our study demonstrated that as the last curative treatment available, (198)Au grain implantation could be used to achieve moderate treatment results for early tongue cancer in patients of advanced age or poor performance status.

Aberrant expression of β- and γ-catenin is an independent prognostic marker in oral squamous cell carcinoma

Alteration in expression of E-cadherin and catenins is associated with loss of differentiation, acquisition of an invasive phenotype and poor clinical outcome in many types of cancer. To identify molecular prognostic markers, membrane expression levels of E-cadherin, and alpha-, beta- and gamma-catenin in biopsy samples (n=135) of oral squamous cell carcinoma (OSCC) were evaluated immunohistochemically in relation to preoperative tumour-related features, clinical course and prognostic value, and were found to be significantly correlated with an endophytic growth pattern and pathologically proved lymph-node metastasis. Alteration of expression of E-cadherin, and alpha-, beta- and gamma-catenin was also significantly correlated with poor disease-specific 5-year survival (P=0.0096, 0.0434, 0.0005 and 0.0005, respectively). Multivariate Cox proportional hazard regression analysis showed that alteration of beta- and gamma-catenin expression was a significantly independent prognostic parameter for survival (P=0.0112 and 0.0088, respectively), as was the case with endophytic growth pattern and advanced N-category. These results indicate that patients with OSCC and absent or reduced membrane expression of beta- and gamma-catenin should be considered a high-risk group for regional lymph-node metastasis and poor prognosis.

Dietary garcinol inhibits 4-nitroquinoline 1-oxide-induced tongue carcinogenesis in rats

The effects of dietary feeding with a polyisoprenylated benzophenone, garcinol, isolated from Garcinia indica fruit rind on the development of 4-nitroquinoline 1-oxide (4-NQO)-induced oral carcinogenesis were investigated in male F344 rats. At 7 weeks of age, animals were given 4-NQO at 20 ppm in the drinking water for 8 weeks to induce tongue neoplasms. They also received the diets containing 100 or 500 ppm garcinol either during (for 10 weeks) or after (for 22 weeks) the carcinogen exposure. The other rats were given tap water without 4-NQO throughout the experiment, and fed garcinol (500 ppm)-containing diet or basal diet alone. At the end of the study (week 32), incidences of tongue neoplasms and preneoplastic lesions, cell proliferation activity in the normal-like tongue epithelium estimated by 5-bromodeoxyurideine (BrdU)-labeling index and cyclin D1-positive cell ratio, and immunohistochemical expression of cyclooxygenase-2 (COX-2) in the tongue lesions were determined. Dietary garcinol significantly decreased the incidence and multiplicity of 4-NQO-induced tongue neoplasms and/or preneoplasms as compared to the control diet. Dietary administration of garcinol also significantly reduced the BrdU-labeling index and cyclin D1-positive cell ratio, suggesting reduction in cell proliferation activity in the tongue by garcinol. The COX-2 expression in the tongue lesions was also suppressed by feeding with garcinol. These results indicate that dietary administration of garcinol inhibited 4-NQO-induced tongue carcinogenesis through suppression of increased cell proliferation activity in the target tissues and/or COX-2 expression in the tongue lesions.

Inhibitory effects of troglitazone, a peroxisome proliferator-activated receptor gamma ligand, in rat tongue carcinogenesis initiated with 4-nitroquinoline 1-oxide

Ligands for peroxisome proliferator-activated receptor (PPAR) gamma have been implicated in growth inhibition and cell differentiation in certain malignancies. In this study, the effects of troglitazone, a PPAR gamma ligand, given during the postinitiation phase of oral carcinogenesis initiated with 4-nitroquinoline 1-oxide (4-NQO) were investigated in male F344 rats. Rats aged 6 weeks were given 4-NQO at 20 ppm for 8 weeks to induce tongue neoplasms. Starting 1 week after the cessation of 4-NQO exposure, animals were fed diets containing 0, 30 or 100 ppm troglitazone for 22 weeks. At the end of the study (week 32), the incidences of 4-NQO-induced tongue neoplasms and preneoplasms were determined histopathologically and cell proliferation activity was estimated by counting bromodeoxyuridine (BrdU)-labeling indices and cyclin D1-positive cell ratios. In addition, immunohistochemical expression of cyclooxygenase (COX)-2 and PPAR gamma was assessed in the tongue lesions. Feeding with 100 ppm troglitazone significantly decreased the incidence of squamous cell carcinoma when compared to the group without troglitazone treatment (5.0% vs. 45.8%, P < 0.005). Interestingly, the BrdU-labeling index and cyclin D1-positive cell ratio assessed in the non-lesional tongue squamous epithelium were reduced by dietary administration of troglitazone (P < 0.0001-0.005). Additionally, the immunoreactivity of COX-2 in the tongue lesions was also decreased by the treatment (P < 0.01-0.05). These results clearly showed that dietary troglitazone inhibits 4-NQO-induced tongue carcinogenesis and such inhibition is related to suppression of increased cell proliferation and/or COX-2 expression. This study warrants further investigation on the use of PPAR gamma ligands as a novel preventive approach for oral malignancy.

The epidemiology of mouth cancer: a review of global incidence

Mouth cancer (143-145 ICD-9) is a major health problem in many parts of the world. While its incidence is relatively low in most western countries there are some important exceptions to this trend: on the Indian subcontinent and in other parts of Asia it remains one of the most common forms of cancer. This review article summarises the global incidence of mouth cancer using cancer maps. Data have been compiled from the latest edition of Cancer Incidence in Five Continents and recent studies from various locations around the world. Significant geographic variation is noted in the incidence of mouth cancer, with high rates reported for the Indian subcontinent and parts of Asia (male incidence rates in excess of 10 per 100,000 per annum). It is also noted that as with other forms of oral cancer, the majority of population-based data for mouth cancer comes from the Western world with a paucity of reliable data from the so-called developing countries. Mouth cancer remains a serious health problem in many parts of the world with many regions reporting increasing incidence rates particularly in males. Ongoing research into the aetiologic risk factors associated with this disease must remain a very high priority if the causes of mouth cancer are to be established and disease control protocols introduced widely.

The epidemiology of tongue cancer: a review of global incidence

The tongue (141 ICD-9) is the most common intraoral site for cancer in most countries, however its global epidemiology shows significant geographic variation. This review paper summarises the global incidence of cancer of the tongue using cancer maps and references to recent studies from various locations. Tongue cancer remains a serious health problem in many countries including India (male incidence rates up to 6.5 per 100,000 per annum) and parts of Europe (male incidence rates in France up to 8.0 per 100,000 per annum). It is noted that as with other forms of oral cancer the majority of population-based data for tongue cancer comes from the Western world with a paucity of reliable data from the so-called developing countries. The tongue remains the most common intraoral site for oral cancer worldwide and in a number of countries it is a serious public health problem with significant morbidity and mortality. While the incidence of tongue cancer appears to be stable or falling in some regions of the world, in other areas it is rising, particularly among younger people.

The epidemiology of lip cancer: a review of global incidence and aetiology

Lip cancer (140 ICD-9) is a form of oral cancer that has a distinctive global epidemiology. This review summarises global incidence rates for male and female lip cancer with the aid of cancer atlases. High male lip cancer rates are reported for regions of North America (12.7 per 100 000 per annum), Europe (12.0 per 100 000 per annum) and Oceania (13.5 per 100 000 per annum), while it is virtually unknown in parts of Asia. Factors commonly cited as important in the aetiology of lip cancer include solar radiation, tobacco smoking and viruses. An attempt is made to summarise the evidence for factors that may be important in lip carcinogenesis. While incidence rates are generally stable or falling among males worldwide, they are rising in many female populations. The aetiology of the disease is far from established and much information regarding its pathogenesis is based on anecdotal rather than case-controlled epidemiological evidence. The epidemiology of lip cancer supports the proposal that the lip should be considered as a distinct cancer site, rather than being included with other forms of intraoral cancer.