CT Perfusion Biomarkers for Ovarian Cancer Treatment Prognosis

Computed tomography perfusion (CTP) biomarkers may help determine progression-free (PFS) survival among women with advanced ovarian cancer, according to a study published in Clinical Cancer Research.

Researchers from the United States and Canada sought to determine if CTP biomarkers were associated with PFS at six months (PFS-6) in patients with advanced ovarian cancer who were treated weekly with carboplatin and either dose-dense or conventional (every three weeks) paclitaxel, with optional bevacizumab in the prospective phase III GOG-0262 trial.

Seventy-six patients, median age 61, participated in this trial. All had residual disease after primary cytoreductive surgery or planned interval cytoreduction following neoadjuvant therapy, to undergo CTP studies before (T0), three weeks (T1), and four weeks (T2) after chemotherapy initiation. Fifty-two of the 76 patients (68%) were neoadjuvant, 24 of the 76 (32%) were suboptimally debulked patients. Thirty-nine of all patients (51%) were

randomized to dose-dense therapy and 37 (49%) to conventional therapy. Sixty-nine (91%) of the evaluable patients received bevacizumab.

The histologic diagnoses among the patients were:

• Ovarian (63 patients)

• Primary peritoneal (7 patients)

• Fallopian tube cancers (6 patients)

Hisologic grades:

• Grade 1: 2

• Grade 2: 7

• Grade 3: 55

• Grade unknown: 12

FIGO stage at diagnosis:

• Stage II: 4

• Stage IIIC: 41

• Stage IV: 31

The results showed that blood volume increase as seen by imaging was significantly associated with lower chance of PFS-6, while tumor blood flow achieved borderline significance (P = 0.053). In addition, blood flow increase was associated with shorter PFS and remained significant after adjusting for age, change in tumor volume, and surgery status. Neither blood flow nor blood volume changes were significantly associated with treatment response rate or overall survival.

"CT perfusion is honing into the change in blood flow to the tumour before and after treatment," co-author Ting-Yim Lee, a professor at Western University's Schulich School of Medicine & Dentistry, scientist at Lawson Health Research Institute, and a medical physicist at St. Joseph's Health Care London, said in a release. "In this particular case we can see that blood flow tends to decrease in those who will survive longer without symptoms, whereas for those whose symptoms will recur within six months, we saw blood flow to the tumour increase after their treatment."

The researchers concluded that early CTP biomarkers measurement may provide early prognostic information for PFS in newly diagnosed ovarian cancer.