TABLE 4.
Multivariable Analysis of Patient, Tumor, and Treatment Factors Associated With Isolated Nodal Basin Recurrence-Free Survival (RFS) and All-Site RFS in Adult Patients With Cutaneous Melanoma and Positive Sentinel Lymph Nodesa
| Isolated Nodal Basin RFS |
All-Site RFS |
|||
|---|---|---|---|---|
| Variable | HR [95% CI] | P | HR [95% CI] | P |
| No. of recurrence events (% of total cohort) | 68 (6) | 220 (19) | ||
| Age per 1-y increase | 1.01 [0.99-1.03] | .41 | 1.00 [0.99-1.01] | .69 |
| AJCC8 stage | NA | <.01c | ||
| IIIA | NAb | Ref | ||
| IIIB | 1.82 [1.08-3.06]c | |||
| IIIC | 3.38 [2.19-5.23]c | |||
| IIID | 4.88 [2.07-11.49]c | |||
| Tumor location | .64 | .03c | ||
| Lower extremity | Ref | Ref | ||
| Upper extremity | 1.21 [0.54-2.73] | 1.32 [0.84-2.09] | ||
| Trunk | 1.43 [0.73-2.82] | 1.16 [0.79-1.70] | ||
| Head/neck | 0.90 [0.34-2.36] | 1.88 [1.21-2.93]c | ||
| No. positive nodes | .67 | .60 | ||
| 1 | Ref | Ref | ||
| 2-3 | 1.01 [0.53-1.95] | 1.20 [0.85-1.69] | ||
| ≥4 | 1.96 [0.44-8.66] | 1.14 [0.53-2.46] | ||
| Extranodal extension | .26 | .52 | ||
| Absent | Ref | Ref | ||
| Present | 1.67 [0.69-4.07] | 1.17 [0.70-1.94] | ||
| Size of SLN metastasis per 1-mm increase | 1.07 [1.02-1.12]c | <.01c | 1.11 [1.06-1.17]c | <.01c |
| Interaction between size of SLN metastasis and follow-up time | NAd | NA | 0.99 [0.98-1.00] | .03c |
| CLND | .02c | .07 | ||
| No | Ref | Ref | ||
| Yes | 0.36 [0.15-0.88]c | 0.68 [0.45-1.02] | ||
| Adjuvant systemic therapy | ||||
| Receipt at any time | 0.77 [0.43-1.37] | .38 | NAe | NA |
| Risk per mo of follow-up: Interaction between adjuvant systemic therapy and time | NAe | NA | 0.52 [0.47-0.57]c | <.01c |
Abbreviations: AJCC8, American Joint Committee on Cancer, eighth edition; CLND, completion lymph node dissection; HR, hazard ratio; NA, not applicable; Ref, reference category; SLN, sentinel lymph node.
Cox proportional hazard models were performed for outcomes of isolated nodal basin RFS and all-site RFS and were adjusted for the variables listed.
AJCC8 stage was not included in the isolated nodal basin RFS model because of the lack of a univariate association with the outcome and failure to meet proportionality of hazards assumptions.
Values denote statistically significant findings; values <1.00 were associated with decreased recurrence, and values >1.00 were associated with increased recurrence.
Values indicate the interaction term for the size of SLN metastasis and the time required for all-site RFS outcome caused by the nonproportionality of hazards.
The association of adjuvant systemic therapy with all-site RFS is reported with an interaction term for time dependence because of the nonproportionality of hazards.