Determinants of patient‐reported xerostomia among long‐term oropharyngeal cancer survivors

Abstract

Background This study was conducted to identify clinicodemographic risk factors for xerostomia among long‐term oropharyngeal cancer (OPC) survivors. Methods This cross‐sectional study included 906 disease‐free, adult OPC survivors with a median survival duration at the time of survey of 6 years (range, 1‐16 years); self‐reported xerostomia scores were available for 877 participants. Study participants had completed curative treatment between January 2000 and December 2013 and responded to a survey administered from September 2015 to July 2016. The primary outcome variable was cancer patient–reported xerostomia measured with the MD Anderson Symptom Inventory Head and Neck Cancer Module. Clinicodemographic risk factors for moderate to severe xerostomia were identified via multivariable logistic regression. Results Moderate to severe xerostomia was reported by 343 of the respondents (39.1%). Female sex (odds ratio [OR], 1.82; 95% CI, 1.22‐2.71; P = .003; Bayesian false‐discovery probability [BFDP] = 0.568), high school or lower education (OR, 1.73; 95% CI, 1.19‐2.52; P = .004; BFDP = 0.636), and current cigarette smoking at the time of survey (OR, 2.56; 95% CI, 1.19‐5.47; P = .016; BFDP = 0.800) were risk factors for moderate to severe xerostomia, and bilateral intensity‐modulated radiotherapy (IMRT) combined with proton therapy and ipsilateral IMRT were protective. Conclusions In this large xerostomia study, modern radiotherapy was a protective factor, and continued cigarette smoking at the time of survey, female sex, and high school or lower education were identified as other contributing risk factors associated with moderate to severe xerostomia. Importantly, these findings need to be confirmed in prospective studies. These results can inform future research and targeted patient‐centered interventions to monitor and manage radiation therapy–associated xerostomia and preserve quality of life among patients with OPC.

Impact of Dose-Volume Parameters of Parotid Glands on Xerostomia in Patients Irradiated for Head-and-Neck Cancer

“…A retrospective study from 2017 with 63 head-and-neck cancer patients also identified the addition of chemotherapy (p<0.05) as a risk factor of xerostomia (13). In a large retrospective cross-sectional study from 2021, patientreported data regarding xerostomia were available for 877 long-term survivors after treatment of oropharynx cancer (9). Approximately 99% of these patients had received radiotherapy.…”

“…However, this can often only be realized if the distribution of the radiation dose at the target volume is compromised, which may result in a higher risk of a locoregional recurrence of the cancer. Several clinical factors have been reported as predictors of xerostomia after radiotherapy of head-and-neck cancers including tumor site (oropharynx, oral cavity), advanced stage, bilateral involvement of lymph nodes and/or irradiation, more advanced age, and concurrent systemic therapies (9)(10)(11)(12)(13). Regarding the impact of dose-volume parameters of radiotherapy on xerostomia, the mean dose to parotid glands was identified as significantly associated with the risk of xerostomia in several studies (10,(14)(15)(16)(17)(18)(19).…”

Genetic susceptibility to patient-reported xerostomia among long-term oropharyngeal cancer survivors

“…Therefore, we also abstracted information on mean dose to parotid glands from medical charts and, using the threshold dose, categorized mean parotid gland dose as follows; ≤ 26 Gy, > 26 Gy, and missing/don’t know. Cigarette smoking status was determined as follows: participants who had not smoked 100 cigarettes in their lifetime were classified as never smokers, those who had quit more than 6 months before diagnosis were considered former smokers at the time of diagnosis 20 , 29 , 30 and finally, current smokers at the time of diagnosis were further categorized into those who quit subsequently and those who continued to smoke 9 , 23 .…”

“…Descriptive statistics were used to summarize the study data and the Kruskal Wallis test and Fishers exact test were used to test for differences between xerostomia categories for continuous and categorical variables, respectively. In a larger study, we had found that sex, education, cigarette smoking, and radiotherapy type were significantly associated with xerostomia; therefore, we adjusted our genetic analyses with these covariates 9 along with mean dose to parotid glands 28 . Quality control for genotype data in our study included: removing SNPs with Hardy–Weinberg equilibrium (HWE; P < 1 × 10 –6 ), genotyping typing call rate ≤ 95%, and minor allele frequency ≤ 0.05 among OPC patients 24 .…”

“…Despite efforts to prevent radiation-attributable salivary gland injury and resultant xerostomia, patient-reported xerostomia was rated in an earlier study as one of the 5 most prevalent and severely rated cancer treatment-associated symptoms among OPC survivors 8 . In a recent study of OPC patients, 39.1% of OPC survivors reported moderate-to-severe xerostomia which had associations with sex, education level, continued smoking, and bilateral intensity modulated radiotherapy (IMRT) after multivariable adjustment 9 .…”