In this study, we observed that oral and swallowing functions returned at 12 months following treatment in patients with early-stage HNC. A total of 32.7% (17/52) patients with early-stage HNC did not return to the BL QOL score at 12M. The patients who did not return to the BL QOL score at 12M indicated a lower QOL than those who returned to BL QOL score at 12M based on the global health status and physical function scores in the EORTC QLQ-C30 and the “sticky saliva” score in the QLQ-H&N35.
The oral functions in both the RE and NR groups returned to the BL at 12M in the present study. Among the total patients included, 32.7% (17/52) were those with tongue cancer. The TP in both the RE and NR groups returned to the BL at 12M. The TP values of patients with tongue cancer decrease following treatment, even in cases that comprise minimal glossectomy . The patients enrolled in this study received indirect and/or direct training such as jaw-opening exercises , tongue-to-palate pressure generation, and tongue muscle exercises. These rehabilitations might improve the patient’s TP.
A previous study has reported that LC in patients with HNC returned to the BL 3 months following treatment . The primary tumor site in their study included the tongue, pharynx, or maxilla. The patients enrolled in the present study included the same primary tumor sites. Therefore, the same tendency as that observed in the previous study might have been observed in our study at 12M. Moreover, no patients with lip cancer were enrolled in this study. Therefore, no significant difference was observed between the mean LC score at BL and that at 12M in both the RE and NR groups. The patients included in this study received rehabilitation as needed. Posttreatment rehabilitation affects the patient's quality of life , and in this study, it was thought to have affected not only results of function measurements but also results of QOL measurements.
Further, the swallowing function and eating ability in the patients with early-stage HNC returned at 12M in our study. Based on the MASA-C scores, only one patient (1/52, 1.9%) reported experiencing dysphagia at 12M. A previous study that focused on patients with early-stage HNC reported excellent swallowing outcomes, assessed using the MD Anderson Dysphagia Inventory (MDADI), within 1 year after treatment . Their study evaluated patient’s QOL using the MDADI questionnaire. Both the present study and their study evaluated dysphagia using assessment tools. On the other hand, some previous studies evaluated dysphagia using videofluoroscopic or video-endoscopic examinations of swallowing [17, 33]. In the present study, we did not evaluate the patients’ swallowing function in terms of penetration and aspiration using videofluoroscopic or video-endoscopic examinations of swallowing. It has been previously reported that 57% of patients with HNC experienced aspiration during fiber-optic endoscopic swallowing evaluation . Penetration and aspiration have been used as the main indicators of dysphagia. However, penetration and aspiration are not necessarily the same as dysphagia. Thus, it is necessary to evaluate the patient’s swallowing function based on both dysphagia using assessment tools, such as MASA-C and MDADI and penetration and aspiration using instrumental assessment, such as videofluoroscopic or video-endoscopic examinations of swallowing.
In a previous report, the swallowing and speech function and QOL-associated parameters in patients with early-stage HNC revealed excellent results . The results of the present study showed the same tendency. The oral and swallowing functions and the swallowing function (swallowing, trouble with social eating, opening mouth, and dry mouth in the EORTC QLQ-H&N 35) and speech function (Speech problems and trouble with social eating form EORTC QLQ-H&N 35) parameters in the QOL assessment returned to the BL at 12M. Another study has reported that the patients’ QOL with T1 and T2 tumor showed good QOL improvement with low symptom scores . That study differs from ours in that it evaluated only early glottic carcinoma and treated it with transoral CO₂ laser microsurgery (TLM), whereas in our study, the patients enrolled had several primary tumor sites and the treatment methods included CRT, RT, and surgical treatment. Moreover, Hendriksma et al. included only T1N0 and T2N0 patients due to TLM indications. Differences in treatment methods (dose of RT, chemotherapy regimens) have different effects on a patient’s QOL . The use of RT is a major determinant of the QOL of patients with cancer . Treatment with primary surgery or primary radiation in patients with HNC has a strong prognostic association with their QOL . Moreover, the addition of chemotherapy to curative radiation indicates a trend toward a worse QOL . The difference in the treatment methods for HNC indicates different morbidities in the swallowing function . Unlike external-beam RT and CRT, surgical treatment has less additional chronic adverse effects on oral function . Furthermore, the health-related QOL of patients with squamous cell carcinoma is not influenced by tumor location . Thus, the difference in the treatment methods is a possible reason for decreased QOL in 33% of patients (17/52) at 12M in the present study.
Our study indicated no significant differences in OM between the RE and NR groups. However, there was a significant difference in the “sticky saliva” score in the QLQ-H&N35 questionnaire between the RE and NR groups. Aging has been reported to affect the salivary glands, salivary flow rate, and quality of saliva . HNC treatment causes xerostomia . However, there were no significant differences in age, sex, and treatment methods between the RE and NR groups in this study. OM and the amount of saliva have been reported to be associated with oral dryness . However, there may not necessarily be a relationship between OM and the properties of saliva . This could explain the present study results, which found no significant difference in OM between the RE and NR groups; however, there might have been differences in the properties of saliva between the groups. Salivary viscosity might have been higher in the NR group than in the RE group, which might have decreased the “sticky saliva” score in the latter group.
This study has several limitations. This study was prospective cohort study that had small sample size because of reduction in the analyzed cases due to participant withdrawal during the study. Patient drop-out during a prospective HNC study is not unusual . This study conducted a single-center study, which relied upon the expertise of the treating clinicians. Further, additional variables, such as the type, dosage, and duration of medications (for example; pain management medications, oral moisturizer), might provide insight into the results of the patients’ QOL. Moreover, the cases in this study included patients with several primary tumor sites who underwent several treatment methods for HNC. Therefore, it is necessary to incorporate larger number of patients and consider additional variables that have the potential to influence the outcomes of this study.