Results
Table 1 summarizes the characteristicsof the cohort of patients. There were 702 consecutive patients with newly diagnosed and untreated HNSCCs with oesophagoscopy and bronchoscopy done at primary diagnosis in the inclusion period. There were 522 male and 180 female patients. The mean age of the patients was 63 years old (range,25-94 years old). There were 393 patients (56%)who were active or ex-smokers, 209 patients (29.8%)who were drinkers or ex-drinkers and 182 patients (25.9%)who were smokers and drinkers.
Majority of sites of primary malignancies were in the oral cavity (356 patients, 50.7%), followed by laryngeal (126 patients, 17.9%), hypopharyngeal (110 patients, 15.7%), oropharyngeal (74 patients, 10.5%) and paranasalsinuses and nasal cavity cancers (33 patients, 4.7%). For staging, most of the patients were having stage 4 disease on presentation (357 patients, 50.9%), whereas there were 162 (23.2%), 92 (13.1%) and 89 (12.7%) patients with stage 1,2 and 3 disease respectively.
The rate of synchronousmalignancies was8.3% (58/702 patients).Figure 1 and 2 shows the Kaplan-Meier survival curve showing overall survival and disease-free survival of the cohort. When comparing between patients with synchronousmalignancies and patients with no synchronousmalignancies (single primary malignancy), the one-year and three-year overall survival (OS) rate were significantly lower in the former group than the latter (one-year OS 40.8% vs 83.25%, P <0.0005; three-year OS 6.8% vs 54.0%, P<0.0005). The same would apply for disease free survival (DFS) rate (one-year DFS 24.5% vs 68.8%, P<0.0005; three-year DFS 6.8% vs 50.1%, P<0.0005).
Characteristics of synchronousmalignancies were delineated in table 2. Among all primary subsites, hypopharynx carried the highest rate of synchronousmalignancies at 27.3% (30/110 patients). There was a relatively low incidence of synchronousmalignancies in other primary subsites. In terms of sites of synchronousmalignancies, most of them occurred in oesophagus (41/58 patients, 73.2%), followed by sites other than the aerodigestive tract(9/58 patients, 15.5%), lung (5/58 patients, 8.9%), head and neck (3/58 patients, 5.4%).
There were three synchronousmalignancies in the head and neck region.Amongst them, two were detectable on clinical examination (one at tongue from a primary hypopharyngeal cancer and another at lower alveolus from a primary cancer at maxillary sinus). The remaining one was at tongue base from a primary retromolar trigone cancer. It was non-suspicious at initial endoscopy but showed increase uptake when working up with PET-CT and therefore biopsy was performed to confirm the malignancy.
The rate of synchronousoesophagealmalignancies was 5.8% (41/702 patients).The majority of the synchronousoesophagealmalignancies were suffering from primary hypopharyngeal cancers (25/41 patients, 61.0%), following by oral cavity cancers (8/41 patients, 19.5%), laryngeal cancers (4/41 patients, 9.8%) and oropharyngeal cancers (4/41 patients, 9.8%). Most of the synchronousoesophagealmalignancies detected were early diseases, with 53.7% of them having stage 1 disease. Risk factors for synchronousoesophagealmalignancies included male gender (Odds ratio OR 14.89, 95% CI: 2.03-109.08), smoker status (OR 3.33, 95% CI: 1.51 – 7.30), drinker status (OR 26.14, 95% CI: 9.18 – 74.40) and primary hypopharyngeal cancer (OR 10.59, 95% CI: 5.43 – 20.64). Out of the 41 patients with synchronousoesophagealmalignancies, 14 of them (34%) wereonly detectable with oesophagoscopy and not by other means of investigation including CT scans of the thorax and PET-CT scans. Therefore, the exclusive detection rate for oesophagoscopy among all subjects was 2.0% (14/702 patients). 4 of these 14 patients were asymptomatic., 13 of themwere having stage 1 diseaseand only 1 of them was having a stage 3 disease. The overall survival and disease-free survivalof patients with oesophagealmalignancies exclusively detectable with oesophagoscopy were significantly better when comparing with other synchronousoesophagealmalignancies not exclusively detected by oesophagoscopy (P = 0.028).
The rate of synchronous lung malignancies was 0.7% (6/702 patients). Among these 6 patients, 4 of themwere detected on chest x-ray, one by PET-CT and one by bronchoscopy. However, all of themwere detectable by PET-CT when being further worked up. Therefore, the exclusive detection rate by bronchoscopy is 0%.
No complications oesophageal or bronchial perforation occurred amongst all patients in the study period. The medianfollow-up period for the cohort of patients was 23 months (Range: 0-120 months).