PCV Chemo Plus Radiation Shows Better Survival in Brain Cancer, Consider Safety

In one study, patients received radiation with chemotherapy, which showed that treatment with a PCV chemotherapy regimen can lead to better survival outcomes.

Newly diagnosed patients with grade 3 oligodendroglioma with mutant IDH 1p/19q codeletion, a rare type of brain cancer, demonstrated improved survival outcomes when treated with a specific regimen of chemotherapy plus radiotherapy compared with temozolomide (TMZ) and radiation.

Oligodendroglioma is a tumor that forms in the brain or spinal cord. When receiving a diagnosis for this type of cancer, it is necessary to find an IDH mutation and a specific change in the chromosomes of the tumor cells, according to the National Cancer Institute. These specific changes are known as 1p/19q codeletion. When cancer is considered grade 3, these tumors are known to grow rapidly.

In a study published in Journal of Clinical Oncologyresearchers evaluated 305 patients newly diagnosed with grade 3 oligodendroglioma with mutant IDH 1p/19q codeletion in a cohort called POLA. Patients were divided into two groups to receive a chemotherapy regimen of procarbazine, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), and vincristine (PCV) plus radiation, or TMZ plus radiation. The PCV plus radiation group included 207 patients and the TMZ plus radiation group included 98 patients.

The average duration of surgery follow-up was 78.4 months for patients in both treatment groups, according to the study. Specifically, the duration of surgery follow-up was 77.6 months in the PCV plus radiation group and 86.3 months in the TMZ plus radiation group.

Study researchers noted that 111 of the 305 patients had a relapse (worsening of the disease after a period of improvement) and 64 patients died.

“In this nationwide observational study, we found that first-line treatment with PCV (plus radiation) was associated with better (overall survival) and long-term (progression) survival) compared with TMZ (plus radiation) in newly diagnosed patients ( grade 3 oligodendroglioma with IDH mutant 1p/19q codeletion),” the researchers wrote in the study.

Survival Outcomes Between Treatment Groups for Oligodendroglioma

Among patients in both treatment groups, overall survival (OS; how long patients live regardless of cancer status) at five and 10 years was 84% ​​and 69%, respectively, researchers said in the study.

Regarding progression-free survival (PFS; time that patients live without signs of worsening or spreading of the disease), PFS at five and 10 years was 67% and 55%, respectively.

Of note, researchers found that patients treated in the PCV plus radiation group had better OS compared to patients who received TMZ plus radiation. At five years in the PCV plus radiation group, OS was 89% versus an OS of 75% in the TMZ plus radiation group, the study showed. Median OS was also not achieved in the PCV plus radiation group, meaning that more patients in this group remained alive longer than anticipated. In the TMZ plus radiation group, the median OS was 140 months, the researchers established.

The study also determined that PFS in patients in the PCV plus radiation group showed improvements compared to patients in the TMZ plus radiation group. At five years, PFS was 75% versus 51% in the PCV and TMZ groups, respectively, the researchers noted. At 10 years, PFS was 67% versus 35%.

Among patients in the PCV group, the median PFS was not reached and was 60 months in patients in the TMZ group, the study stated.

Side effects associated with both treatments in oligodendroglioma

Although patients in the PCV group had better OS and PFS outcomes, the researchers emphasized that it is important to consider the side effects associated with these treatments.

They noted that based on previous trials, including the EORTC 26951 trial published in Journal of Clinical Oncology“38% of patients were unable to complete the PCV regimen due to hematologic (blood) or non-hematologic toxicity,” they wrote.

In the POLA cohort, investigators also observed a similar number of chemotherapy interruptions in patients. Specifically, 36% of patients in the PCV group did not receive six cycles of chemotherapy, the study noted.

However, TMZ’s safety profile was associated with more favorable outcomes, researchers said. An earlier trial, CATNON, published in Lancet Oncology demonstrated that 15% of patients who received pre-surgical TMZ experienced grade 3 or 4 (severe to life-threatening) hematological side effects.

“Despite these results supporting the use of PCV(plus) RT rather than TMZ(plus) RT, the safety profile of PCV remains challenging,” the researchers wrote.

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