Oral cancer has a low 5-year survival rate compared with other major types of cancer, and the rate hasn’t improved much in recent years, say researchers from China Medical University, Asia University, Taichung Veterans General Hospital, and National Yang-Ming University; all in Taichung, Taiwan. That may be due in part to delay in treatment, they say. Their analysis of data of 21,263 patients with oral cavity squamous cell carcinoma (OCSCC) bears out their theory.
About 40% of the patients presented with stage IV disease. More than one-third had tongue cancer. The average time from diagnosis to treatment was 24 days. Most patients (86%) were treated within 30 days of diagnosis; 12% were treated between 31 and 120 days after diagnosis, and 2.7% received treatment 120 days after diagnosis. Surgery was usually the first treatment.
The time interval from diagnosis to treatment (the phrase the researchers prefer to “treatment delay” or “wait time”) was an independent prognostic factor in OCSCC patients. The average interval was 24 days. Those treated within 30 days tended to have a higher survival rate. Treatment after 120 days from diagnosis increased the risk of death by 1.32-fold.
The average follow-up period was 44 months. When the researchers stratified patients according to the time between diagnosis and treatment, they found patients aged ≥ 65 years or who had advanced cancer were more likely to be treated later. Patients treated initially with radiotherapy or chemotherapy were more likely to have a longer mean time interval when compared with those who were treated first with surgery.
The researchers also found that patients treated in private hospitals had a shorter time interval compared with those treated in public hospitals (although the latter were more likely to survive). Patients who received treatment in hospitals with a low- to medium-service volume had a longer interval compared with those treated in hospitals with a high-service volume. Other predictors of longer survival included being female, younger, primary tumor site at the tongue, and earlier stage disease.
The researchers cite a study that found the median duration of clinical upstaging from early to late stage was 11.3 months, whereas the average period from advanced tumor to untreatable tumor was 3.8 months. That might explain why they found that the longer delay to treatment increased the risk of death, they suggest. The researchers also point to reasons such as pending second opinions, shortages of therapeutic instruments and manpower, and lack of public awareness.
All told however, the researchers conclude, the reasons for the increased time interval from diagnosis to treatment of OCSCC patients remain “multifaceted, integrated, and poorly understood.”
Tsai WC, Kung PT, Wang YH, Huang KH, Liu SA. PLoS One. 2017;12(4):e0175148.