2017 Section 7 Green Book

S URGICAL MANAGEMENT OF OROPHARYNGEAL SCC

TABLE 3. Multivariable analysis of outcome predictors.

Analysis

Overall, n 5 260

HPV negative, n 5 108

HPV positive, n 5 152

Variables

HR

95% CI

p value

HR

95% CI

p value

HR

95% CI

p value

Approach

Transoral

Ref

Ref

Ref

Open

1.343 0.788–2.288 .2784

0.79

0.4–1.561

.4984

3.09 1.293–7.385 .0111

Extranodal extension No

Ref

Ref

Ref

Yes

1.938 1.262–2.976 .0025 2.322 1.359–3.968 .0021 1.119 0.536–2.335 .7644

HPV

Positive Negative

Ref

2.362 1.496–3.731 .0002

N/A

N/A

N/A

N/A

N/A

N/A

Mucosal margins

Free of carcinoma

Ref

Ref

Ref

Positive

1.621 0.969–2.711 .0656 1.213 0.614–2.395 .5787 2.519 1.101–5.766 .0287

Perineural invasion No

Ref

Ref

Ref

Yes

1.398 0.901–2.17

.1347 1.407 0.82–2.414

.2153

1.14 0.514–2.529 .7466

Smoking status

10 pack-years > 10 pack-years

Ref

Ref

Ref

1.316 0.763–2.27

.3235 1.452 0.637–3.311 .3747 1.302 0.616–2.751 .4894

T classification T1/T2

Ref

Ref

Ref

T3/T4

1.937 1.187–3.16

.0081 2.029 1.054–3.906 .0342 2.125 0.983–4.595 .0555

Abbreviations: HPV, human papillomavirus; HR, hazard ratio; 95% CI, 95% confidence interval.

Effect of adjuvant therapy on survival In this cohort, patients either underwent surgery alone ( n 5 26), surgery with postoperative radiotherapy ( n 5 89), or surgery with postoperative chemoradiotherapy ( n 5 143). In the remaining patients ( n 5 38), the data were incomplete with regard to adjuvant therapy, and these patients with missing data were excluded from the multi- variable analysis. Multivariable analysis showed that there was no signifi- cant difference in survival in patients treated with surgery alone, surgery with adjuvant radiation, or surgery with adjuvant chemoradiation. The small number of patients treated with surgery alone made statistical comparisons between this group of patients and those receiving adju- vant radiation or chemoradiation treatment underpowered. However, the robust number of patients receiving adju- vant radiation treatment ( n 5 89) and adjuvant chemora- diation treatment ( n 5 143) allowed us to draw meaningful statistical comparisons between these groups. After controlling for all other variables, no difference in survival was seen between patients treated with surgery with adjuvant radiation versus surgery with adjuvant che- moradiation ( p 5 .6306). In the HPV-positive subgroup, no difference was seen in patients treated with surgery with adjuvant radiation versus surgery with adjuvant che- moradiation ( p 5 .4707). Similarly, in the HPV-negative subgroup, no difference was seen in patients treated with surgery with adjuvant radiation versus surgery with adju- vant chemoradiation ( p 5 .8493). Gastrostomy tube outcomes In an effort to determine functional outcomes in this cohort, the presence of a gastrostomy tube was docu-

mented. Patients were included based on the presence of a gastrostomy tube, rather than gastrostomy tube depend- ence, and this group included patients who were using the gastrostomy tube for at least a portion of their diet. Gas- trostomy tubes were present in 12.8%, 23.3%, and 32.1% of patients at 1, 3, and 5 years, respectively. Gastrostomy tube dependence rates were impacted by surgical approach, with the open approach cohort accounting for the majority of patients who were gastrostomy tube dependent. Gastrostomy tube presence was lowest in patients with T1/T2 tumors undergoing transoral resec- tion, whereas the rate of tube dependence was 7.84% for T1/T2 classification and 9.52% in patients with T3/T4 classification (Table 4). DISCUSSION This study provides strong evidence that HPV status is the most important predictor of overall survival in a large, surgically treated oropharyngeal SCC cohort. For the entire cohort, 3 and 5 year survival rates were 71.3% and 65.1%, respectively. However, for HPV-positive patients, survival rates at 3 and 5 years were 83.3% and 81.8%, respectively, compared to 53.3% and 40.3% for HPV- negative patients. These outcomes are comparable to che- moradiotherapy trials for the same disease site. 13 When adjusting for other covariates (surgical approach, mucosal margins, perineural invasion, and smoking status), HPV status, ECS, and tumor classification were significantly associated with overall survival. Unlike previously reported primary chemoradiation studies, smoking status, stratified risk levels, and neck disease did not impact sur- vival in surgically treated patients. 15

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