Table 1:
Characteristics and distribution of OPC Patients (N = 906) by clinic-demographic factors
| Variables | All OPC pt. (N=906) | Xerostomia Information Missing (N=29) | Xerostomia none to mild (N=534) | Xerostomia moderate to severe (N=343) | P |
|---|---|---|---|---|---|
| Age at diagnosis, y median (range, IQR), (mean ±SD) | 56 (32–84, 51–63), (56.9 ±8.8) | 0 | 56 (32–84, 51–62), (56.7 ±9.0) | 56 (33–82, 51–63), (57.1 ±8.7) | 0.641 |
| Survival time, y median (range, IQR), (mean ±SD) | 6 (1–16, 4–10), (7.0±3.9) | 0 | 7 (2–16, 4–10), (7.1 ±3.8) | 6 (1–16, 4–10), (6.9 ±4.0) | 0.398 |
| Radiation Dose, Gy median (range, IQR), (mean ±SD) | 70 (40–72.6, 66–70), (68.1 ±2.6) | 0 | 69.2 (57–72, 66–70), (68.0 ±2.5) | 70.0 (40–72.6, 66–70), (68.3 ±2.8) | 0.103 |
| Sex | 0.007 | ||||
| Female | 140 (15.5) | 8 | 66 (50.0) | 66 (50.0) | |
| Male | 766 (84.6) | 21 | 468 (62.8) | 277 (37.2) | |
| Education | 0.004 | ||||
| >Highschool | 650 (71.7) | 18 | 406 (64.2) | 226 (35.8) | |
| ≤ Highschool | 171 (18.9) | 8 | 83 (50.9) | 80 (49.1) | |
| Missing | 85 (9.4) | 3 | 45 (54.9) | 37 (45.1) | |
| Race/Ethnicity | 0.817 | ||||
| Non-Hispanic white | 837 (92.4) | 25 | 494 (60.8) | 318 (39.2) | |
| Non-Hispanic black | 17 (1.9) | 1 | 10 (62.5) | 6 (37.5) | |
| Hispanics | 35 (3.8) | 2 | 22 (66.7) | 11 (33.3) | |
| Other | 8 (0.9) | 1 | 3 (42.9) | 4 (57.1) | |
| Missing | 9 (1.0) | 0 | 5 (55.6) | 4 (44.4) | |
| Primary Site | 0.779 | ||||
| Tonsil | 418 (46.1) | 11 | 253 (62.2) | 154 (37.8) | |
| Base of Tongue + GPS | 456 (50.3) | 17 | 262 (59.7) | 177 (40.3) | |
| Other | 32 (3.5) | 1 | 19 (61.3) | 12 (38.7) | |
| T classification | 0.171 | ||||
| 1 | 335 (37.0) | 16 | 202 (63.3) | 117 (36.7) | |
| 2 | 349 (38.5) | 6 | 211 (61.5) | 132 (38.5) | |
| 3 | 134 (14.8) | 3 | 79 (60.3) | 52 (39.7) | |
| 4 | 88 (9.7) | 4 | 42 (50.0) | 42 (50.0) | |
| N classification | 0.190 | ||||
| N0 | 83 (9.2) | 3 | 51 (63.8) | 29 (36.3) | |
| N1+2a | 239 (26.4) | 8 | 146 (63.2) | 85 (36.8) | |
| 2b+3 | 434 (47.9) | 10 | 262 (61.8) | 162 (38.2) | |
| 2c | 150 (16.6) | 8 | 75 (52.8) | 67 (47.2) | |
| HPV status | 0.540 | ||||
| Negative | 58 (6.4) | 2 | 32 (57.1) | 24 (42.8) | |
| Positive | 440 (48.6) | 14 | 254 (59.6) | 172 (40.4) | |
| Unknown | 408 (45.0) | 13 | 248 (67.8) | 147 (37.2) | |
| Cigarettes Smoking | 0.029 | ||||
| Never | 420 (46.3) | 12 | 252 (61.8) | 156 (38.2) | |
| Former smokers at time of diagnosis | 343 (37.9) | 9 | 212 (63.5) | 122 (36.5) | |
| Quit smoking subsequent to diagnosis | 95 (10.5) | 6 | 51 (57.3) | 38 (42.7) | |
| Current smoker | 36 (4.0) | 2 | 12 (35.3) | 22 (64.7) | |
| Don’t know | 12 (1.3) | 0 | 7 (58.3) | 5 (41.7) | |
| Solid Food pre-Tx | 0.759 | ||||
| Yes | 894 (98.7) | 28 | 528 ((61.0) | 338 (39.1) | |
| No | 12 (1.3) | 1 | 6 (54.6) | 5 (45.4) | |
| Treatment Group | 0.155 | ||||
| Single Modality | 280 (30.9) | 9 | 175 (64.6) | 96 (35.4) | |
| Multimodality | 626 (69.1) | 20 | 359 (59.2) | 247 (40.8) | |
| Treatment Group | 0.069 | ||||
| RT alone | 272 (30.0) | 9 | 167 (63.5) | 96 (36.5) | |
| Surgery alone | 8 (0.9) | 0 | 8 (100.0) | 0 (0.0) | |
| RT plus systemic | 610 (67.3) | 19 | 350 (59.2) | 241 (40.8) | |
| Surgery plus adjuvant | 16 (1.8) | 1 | 9 (60.0) | 6 (40.0) | |
| Chemotherapy | 0.118 | ||||
| No | 286 (31.6) | 10 | 179 (64.9) | 97 (35.1) | |
| Yes | 620 (68.4) | 19 | 355 (59.1) | 246 (40.9) | |
| Surgery | 0.110 | ||||
| No | 881 (97.2) | 28 | 516 (60.5) | 337 (39.5) | |
| Yes – Robotic | 18 (2.0) | 0 | 15 (83.3) | 3 (16.7) | |
| Yes – Open | 7 (0.8) | 1 | 3 (50.0) | 3 (50.0) | |
| Neck Dissection | 0.203 | ||||
| No | 679 (74.9) | 22 | 392 (59.7) | 265 (40.3) | |
| Yes | 227 (25.1) | 7 | 142 (64.5) | 78 (35.5) | |
| Radiotherapy | 0.026 | ||||
| No | 8 (0.9) | 0 | 8 (100.0) | 0 (0.0) | |
| Yes | 898 (99.1) | 29 | 526 (60.5) | 343 (39.5) | |
| RT Schedule | 0.045 | ||||
| Standard Fractionation | 798 (88.1) | 25 | 471 (60.9) | 302 (39.1) | |
| Accelerated | 100 (11.0) | 4 | 55 (57.3) | 41 (42.7) | |
| Missing/No RT | 8 (0.9) | 0 | 8 (100.0) | 0 (0) | |
| RT Type | <0.001 | ||||
| 3d Conformal | 51 (5.6) | 2 | 20 (40.8) | 29 (59.2) | |
| IMRT Bilateral (SF+WF+VMAT) + Proton | 747 (82.5) | 21 | 438 (60.3) | 288 (39.7) | |
| IMRT Ipsilateral | 100 (11.0) | 6 | 68 (72.3) | 26 (26.7) | |
| Missing/No RT | 8 (0.9) | 0 | 8 (100.0) | 0 (0.0) | |
| Induction Chemotherapy | 0.047 | ||||
| No | 609 (67.2) | 21 | 372 (63.3) | 216 (36.7) | |
| Yes | 297 (32.8) | 8 | 162 (56.1) | 127 (43.9) | |
| Concurrent Chemotherapy | 0.298 | ||||
| No | 418 (46.1) | 15 | 253 (62.8) | 150 (37.2) | |
| Yes | 488 (53.9) | 14 | 281 (59.3) | 193 (40.7) | |
| Induction and Concurrent Chemotherapy | 0.075 | ||||
| No | 739 (81.6) | 25 | 445 (62.3) | 269 (37.7) | |
| Yes | 167 (18.4) | 4 | 89 (54.6) | 74 (45.4) | |
| Concurrent high dose cisplatin | 0.375 | ||||
| No | 809 (89.3) | 27 | 472 (60.4) | 310 (39.6) | |
| Yes | 97 (10.7) | 2 | 62 (65.3) | 33 (34.7) | |
| Concurrent low dose weekly cisplatin | 0.195 | ||||
| No | 779 (86.0) | 25 | 466 (61.8) | 288 (38.2) | |
| Yes | 127 (14.0) | 4 | 68 (55.3) | 55 (44.7) | |
| Concurrent carboplatin weekly | 0.010 | ||||
| No | 820 (90.5) | 27 | 494 (62.3) | 299 (37.7) | |
| Yes | 86 (9.5) | 2 | 40 (47.6) | 44 (52.4) | |
| Concurrent cetuximab weekly | 0.095 | ||||
| No | 754 (83.2) | 23 | 436 (59.6) | 295 (40.4) | |
| Yes | 152 (16.8) | 6 | 98 (67.1) | 48 (32.9) | |
| Xerostomia During RT | 0.285 | ||||
| No | 257 (28.4) | 8 | 149 (59.8) | 100 (40.2) | |
| Yes | 637 (70.3) | 21 | 375 (60.9) | 241 (39.1) | |
| Missing/No RT | 12 (1.3) | 0 | 10 (83.3) | 2 (16.7) |
Note: One patient was excluded due to missing filling out the MDASI-HN. Twenty-nine patients did not answer the Xerostomia question on the MDASI-HN. Self-reported xerostomia scores were available for 877 participants.
Solid food diet pre-treatment was controlled for as a surrogate control for pre-treatment oral dysfunction/symptoms.
Primary tumor T categories included T1 (including Tx), T2, T3, and T4 (including both T4a and T4b).
RT dose was total radiation dose measured in Gray (Gy).
RT fractionation schedule included standard fractionation (70.0 Gy given in 33–35 fractions), accelerated fractionation (72.0 Gy given in 40 fractions or use of concomitant boost or Danish Head and Neck Cancer Group RT regimens), and no RT.
RT types included 3-dimensional conformal RT (3D-CRT); bilateral intensity modulated RT (IMRT) with split-field (IMRT-SF), whole-field (IMRT-WF), volumetric-modulated arc therapy (VMAT) and proton therapy; and ipsilateral IMRT regimens
Abbreviations: IQR, interquartile range, T, tumor; RT, radiotherapy; 3D-CRT; three-dimensional conformal radiotherapy, IMRT-SF, Intensity modulated radiotherapy split-field technique; IMRT-WF, Intensity modulated radiotherapy whole-field technique; VMAT, Volumetric-modulated arc therapy