Oxygenation of Human Tumors

Darbepoetin alfa for the treatment of chemotherapy-induced anemia: disease progression and survival analysis from four randomized, double-blind, placebo-controlled trials

PURPOSE

To determine the effect of darbepoetin alfa (DA) on progression-free survival (PFS) and overall survival (OS) in patients with chemotherapy-induced anemia (CIA).

PATIENTS AND METHODS

Two 16-week randomized, double-blind, placebo-controlled phase III studies of weekly DA in anemic patients with lung cancer (n = 314) or lymphoproliferative malignancies (LPMs; n = 344) undergoing chemotherapy were analyzed with prospectively defined long-term PFS and OS end points. Short-term effects of DA on PFS and OS were analyzed by including two additional 16-week dose-finding, double-blind, placebo-controlled studies in anemic patients with multiple tumor types (n = 405) and LPMs (n = 66).

RESULTS

Median follow-up is 15.8 months (lung cancer) and 32.6 months (LPM). Median duration of PFS was comparable between DA and placebo: 5.1 months (95% CI, 4.1 to 6.9 months) versus 4.4 months (95% CI, 3.7 to 5.3 months) for lung cancer and 14.2 months (95% CI, 12.2 to 17.5 months) versus 15.9 months (95% CI, 13.1 to 19.0 months) for LPMs. The estimated hazard ratio (HR) of death related to DA use for lung cancer was 0.77 (95% CI, 0.59 to 1.01) and 1.26 (95% CI, 0.92 to 1.71) for LPMs. In the pooled analyses of all four studies (n = 1,129), no differences in PFS or OS were observed between DA and placebo (HR = 0.92; 95% CI, 0.78 to 1.07; and HR = 0.95; 95% CI, 0.78 to 1.16, respectively).

CONCLUSION

Treatment with DA does not seem to influence PFS or OS in patients with CIA. Prospective, randomized clinical trials will provide additional insights into the effects of DA on PFS and OS in specific tumor types.

Severe anemia is associated with poor tumor oxygenation in head and neck squamous cell carcinomas

PURPOSE

To investigate the relationship between tumor oxygenation and the blood hemoglobin (Hb) concentration in patients with squamous cell carcinoma of the head and neck (SCCHN).

METHODS AND MATERIALS

A total of 133 patients with SCCHN underwent pretreatment polarographic pO2 measurements of their tumors. In 66 patients measurements were also made in sternocleidomastoid muscles. The patients were divided into three groups according to their Hb concentration-severe anemia (Hb < 11.0 g/dl), mild anemia (female: Hb 11.0-11.9 g/dl; male: Hb 11.0-12.9 g/dl), and normal Hb concentration (female: Hb > or =12.0 g/dl; male: > or =13.0 g/dl).

RESULTS

No significant difference in tumor oxygenation could be detected between mildly anemic patients and patients with a normal Hb level. However, the tumor oxygenation in the severely anemic group was significantly below that of each of the other two groups (p < 0.0001). There was no significant difference between the Hb groups in oxygenation of sternocleidomastoid muscles. In a multivariate analysis including Hb group, tumor volume, smoking habits, gender, T-stage, N-stage, and histologic grade a Hb level < 11 g/dl was found to be the strongest predictor for a poor tumor oxygenation. Smoking also had a marginal influence on median pO2.

CONCLUSION

Our data suggest that a low Hb concentration and cigarette smoking contribute to inadequate oxygenation of SCCHN and thus for increased radioresistance. Consequently, Hb correction and abstinence from smoking may significantly improve tumor oxygenation.