PMC

Figure 1. Overall survival of all PV and all control patients.

Figure 2. Overall survival of all PV and all control patients who had clinically palpable or nonpalpable lymph node metastases.

Figure 3. Overall survival of all PV and all control patients by tumor burden: one positive node, two or three positive nodes, or four or more positive nodes.

Figure 5. Overall survival of 739 pairs of PV and control patients matched by six prognostic factors: number of positive nodes, nodal size, primary T stage, ulceration, sex, and age.

Figure 4. Overall survival according to time of treatment (before or after January 1, 1985). (Left) All PV and all control patients. (Right) 447 pairs of control patients matched by tumor burden, nodal status, primary T stage, and ulceration.