Drug therapy in diarrheal diseases in oncology/hematology patients

Targeting vascular endothelial growth factor in advanced carcinoid tumor: a random assignment phase II study of depot octreotide with bevacizumab and pegylated interferon alpha-2b

PURPOSE

Effective systemic therapy for advanced carcinoid is lacking. The combination of bevacizumab (BEV) and pegylated (PEG) interferon alpha-2b was evaluated among patients with metastatic or unresectable carcinoid tumors.

PATIENTS AND METHODS

Forty-four patients on stable doses of octreotide were randomly assigned to 18 weeks of treatment with bevacizumab or PEG interferon alpha-2b. At disease progression (PD) or at the end of 18 weeks (whichever occurred earlier), patients received bevacizumab plus PEG interferon until progression. Functional computer tomography (CT) scans were performed to measure effect on tumor blood flow.

RESULTS

In the bevacizumab arm, four patients (18%) achieved confirmed partial response (PR), 17 patients (77%) had stable disease (SD), and one patient (5%) had PD. In the PEG interferon arm, 15 patients (68%) had SD and six patients (27%) had PD. Progression-free survival (PFS) rates after 18 weeks of monotherapy were 95% in bevacizumab versus 68% on the PEG interferon arm. The overall median PFS for all 44 patients is 63 weeks. Compared with paired baseline measurements on functional CT scans, we observed a 49% (P < .01) and 28% (P < .01) decrease in tumor blood flow at day 2 and week 18 among patients treated with bevacizumab. No significant changes in tumor blood flow were observed following PEG interferon. PEG interferon alpha-2b treatment was associated with decrease in plasma basic fibroblast growth factor (bFGF; P = .04) and increase in plasma interleukin-18 (IL-18; P < .01). No significant changes in bFGF or IL-18 following treatment with bevacizumab were observed.

CONCLUSION

Bevacizumab therapy resulted in objective responses, reduction of tumor blood flow, and longer PFS in patients with carcinoid than PEG interferon treatment.

Cancer chemotherapy-induced diarrhoea and constipation: mechanisms of damage and prevention strategies

BACKGROUND

Diarrhoea and constipation are common toxicities of chemotherapy, and both are poorly understood. They are manifestations of alimentary mucositis, a condition which affects the entire gastrointestinal tract.

DISCUSSION

The absolute percentage of patients that have diarrhoea or constipation as a result of their treatment has yet to be fully defined, although general estimates place 10% of patients with advanced cancer as being afflicted. Although there has been some major progress in recent years with understanding the mechanisms of oral and small intestinal mucositis, diarrhoea and constipation have received very little attention. Although diarrhoea is a well-recognised side-effect of both chemotherapy and radiotherapy, very little research has been conducted on the mechanisms behind diarrhoea or its treatment. Much of the information in the published literature is based on clinical observations with very little basic science existing. Constipation is not as well recognised and very little is known about its mechanisms.

OBJECTIVES

This review will examine in detail the potentially complex pathogenesis of post-chemotherapy diarrhoea in both animal models and the clinical setting. Furthermore, it will explore what is known about chemotherapy-induced constipation. It will then outline an evidence-based pathway for the investigation and treatment of post-chemotherapy diarrhoea and constipation.

The Assessment and Management of Cancer Treatment–Related Diarrhea

Cancer treatment-induced diarrhea affects a high percentage of patients with cancer that receive chemotherapy or radiation treatment. Widely used criteria for measuring treatment-induced diarrhea, such as the National Cancer Institute Common Toxicity Criteria, do not account for important characteristics of treatment-induced diarrhea. These characteristics include the assessment of the duration of the diarrhea, coexisting symptoms, abdominal cramping, or the presence of nocturnal diarrhea. Until recently, there were no universally accepted guidelines for the management of diarrhea. An expert panel developed guidelines with recommendations regarding assessment of the patient and treatment. These guidelines stress the importance of a thorough assessment of the patient, and treatment based upon severity of symptoms. By employing these guidelines, the aggressive management of diarrhea may impact the overall morbidity of this symptom. Education regarding the importance of diarrhea is essential. Patients who are informed will better understand their role in managing this side effect and when to contact their health care provider with emergent symptoms. Early recognition and management of diarrhea will be essential to improve control of diarrhea, and in turn will positively impact patients' quality of life.

Have enteric infections a role in 5-fluorouracil-associated diarrhea?

In 16 advanced colorectal cancer patients with 5-fluorouracil-associated diarrhea, we evaluated the role of bacterial pathogens in the development of this adverse effect. Neither Clostridium difficile nor other pathogens were cultured from fecal specimens. These data seem to suggest that it is unlikely that intestinal infections have a role in the pathogenesis of 5FU-associated diarrhea.