Table 1.
Baseline characteristics and comparison between arms
|
Placebo arm n = 29 |
NAC arm n = 28 |
P value | |
|---|---|---|---|
| Age mean ± SD, years | 56.6 ± 7.8 | 55.9 ± 8.8 | 0.8354(a) |
| BMI mean ± SD, kg/m2 | 22.6 ± 4.9 | 22.0 ± 3.2 | 0.8729(a) |
| Gender, n (%) | 0.6701(b) | ||
| Men | 27 (93.1) | 25 (89.3) | |
| Women | 2 (6.9) | 3 (10.7) | |
| Race, n (%) | 0.7297(b) | ||
| White | 23 (79.3) | 24 (85.7) | |
| Non‐white | 6 (20.7) | 4 (14.3) | |
| Smoking category, n (%) | 0.1646(c) | ||
| Non‐smokers | 1 (3.4) | 4 (14.3) | |
| Light smokers | 1 (3.4) | 3 (10.7) | |
| Moderate smokers | 3 (10.4) | 2 (7.1) | |
| Heavy smokers | 24 (82.8) | 19 (67.9) | |
| Drinking category, n (%) | 0.2798 (c) | ||
| Abstainers | 2 (6.9) | 3 (10.7) | |
| Light drinkers | 0 (0.0) | 0 (0.0) | |
| Moderate drinkers | 7 (24.1) | 2 (7.1) | |
| Heavy drinkers | 7 (24.1) | 6 (21.4) | |
| Very heavy drinkers | 13 (44.9) | 17 (60.8) | |
| KPS, n (%) | 0.5575 (b) | ||
| 100 | 2 (6.9) | 4 (14.3) | |
| 90 | 21 (72.4) | 17 (60.7) | |
| 80 | 6 (20.7) | 7 (25.0) | |
| Tumor site, n (%) | 0.9034 (c) | ||
| Oropharynx | 15 (51.8) | 15 (53.6) | |
| Larynx | 8 (27.6) | 9 (32.2) | |
| Oral cavity | 4 (13.8) | 2 (7.1) | |
| Hypopharynx | 1 (3.4) | 2 (7.1) | |
| Oropharynx +oral cavity (synchronic tumors) | 1 (3.4) | 0 (0.0) | |
| Tumor differentiation, n (%) | 0.7348 (b) | ||
| Well differentiated | 1 (3.5) | 3 (10.7) | |
| Moderately differentiated | 17 (58.6) | 19 (67.9) | |
| Poorly differentiated | 3 (10.3) | 3 (10.7) | |
| Undifferentiated | 0 (0.0) | 0 (0.0) | |
| Not evaluated | 8 (27.6) | 3 (10.7) | |
| T stage, n (%) | 0.9164 (c) | ||
| T1 | 1 (3.5) | 1 (3.6) | |
| T2 | 5 (17.2) | 2 (7.1) | |
| T3 | 5 (17.2) | 6 (21.4) | |
| T4 | 18 (62.1) | 17 (60.8) | |
| Tx | 0 (0.0) | 2 (7.1) | |
| N stage, n (%) | 0.3514 (c) | ||
| N0 | 6 (20.7) | 4 (14.3) | |
| N1 | 2 (6.9) | 5 (17.8) | |
| N2 | 17 (58.6) | 18 (64.3) | |
| N3 | 4 (13.8) | 1 (3.6) | |
| Stage, n (%) | 0.1086 (c) | ||
| I | 0 (0.0) | 1 (3.6) | |
| II | 1 (3.4) | 0 (0.0) | |
| III | 0 (0.0) | 3 (10.7) | |
| IV | 28 (96.6) | 24 (85.7) | |
| Comorbidities, n (%) | 0.5027 (c) | ||
| Systemic arterial hypertension | 11 (37.9) | 4 (14.3) | |
| Diabetes mellitus | 3 (10.3) | 4 (14.3) | |
| Arrhythmia and other cardiovascular diseases, except SAH | 2 (6.9) | 0 (0.0) | |
| Depression | 2 (6.9) | 0 (0.0) | |
| Gastroesophageal reflux disease | 1 (3.4) | 1 (3.6) | |
| Hypothyroidism | 1 (3.4) | 1 (3.6) | |
| Arthrosis | 1 (3.4) | 1 (3.6) | |
| Other | 4 (13.8) | 4 (14.3) |
BMI: Body Mass Index, KPS: Karnofsky Performance Status, n: absolute number, SAH: Systemic arterial hypertension, SD: standard deviation. (a)Mann‐Whitney test, (b)Fisher's exact test, (c)Chi‐square test.
Groups were formed to perform the statistical tests for the following categories: smoking = heavy smokers vs moderate + light + non‐smokers; drinking = very heavy + heavy drinkers vs moderate + light drinkers + abstainers; tumor site = oropharynx vs other sites; tumor differentiation = moderately differentiated vs well + poorly differentiated + undifferentiated; T stage = T4 vs T1 + T2 + T3; N stage = N0 + N1 vs N2 + N3; stage = IV vs I + II + III; comorbidities = have comorbidities vs have no comorbidities.
Smoking category was classified based on the study by Jindal et al20. Patients were classified as non‐smokers if they reported never having smoked; light, moderate, and heavy smokers were smokers and ex‐smokers, and they were classified according to the smoking index (SI), which was the product of the average number of cigarettes smoked per day and the duration of smoking in years; light (SI = 1‐100), moderate (SI = 101‐300), and heavy (SI ≥ 301) smokers.
Drinking category was classified based on the study by Whitcomb et al21. Average weekly alcohol intake during the maximum lifetime drinking period (drinks/wk): abstainers, no alcohol use or <20 drinks in lifetime; light drinkers, ≤3 drinks/wk; moderate drinkers, 4‐7 drinks/wk for females and 4‐14 drinks/wk for males; heavy drinkers, 8‐34 drinks/wk for females and 15‐34 drinks/week for males; very heavy drinkers, ≥35 drinks/week.
Other comorbidities: asthma, bronchitis, chronic obstructive pulmonary disease, fibromyalgia, hepatic cirrhosis, hepatitis B, hypercholesterolemia, labyrinthitis.