Correlations between leukocyte count and absolute granulocyte count in patients receiving cancer chemotherapy

FOLFOX chemotherapy can safely be given to neutropenic patients with early-stage colorectal cancer for higher dose intensity and fewer visits

PURPOSE

How does giving adjuvant FOLFOX chemotherapy to patients with early-stage colorectal cancer (ESCRC) regardless of the day-before absolute neutrophil counts (ANC) effect chemotherapy-induced febrile neutropenia (CIFN) rates, received dose intensity (RDI), and chemotherapy cycle delay? Does an ANC level predict future neutropenia?

METHODS

A retrospective chart review was conducted on all patients receiving adjuvant chemotherapy for ESCRC at a mid-sized community hospital in Toronto, Ontario, Canada between April 2005 and May 2014. All patients were under one medical oncologist. Day-before CBC data were collected along with other patient characteristics. CIFN was confirmed by hospital records. Inclusion criteria were met by 132 patients. Overall, 1074 cycles of chemotherapy were analyzed.

RESULTS

Six episodes of CIFN were observed. There was a significant difference in the average day-before ANC between patients who developed CIFN (1.4 × 10(9)/L, 95 % CI 0.76-2.0 × 10(9)/L) and those who did not (2.9 × 10(9)/L, 95 % CI 2.8-3.0 × 10(9)/L, p = 0.03). The RDI for oxaliplatin was 0.95 and for 5-fluorouracil (5-FU) was 0.96. A total of 170 cycles were given at day-before ANC <1.5 × 10(9)/L (range 0.1 × 10(9)/L-1.4 × 10(9)/L), and 24 were delayed for 1 week for hematologic reasons. Cycles given with grade 2 neutropenia predicted higher grades of neutropenia with a sensitivity of 0.22 (95 % CI 0.12-0.38).

CONCLUSIONS

Adjuvant FOLFOX chemotherapy may be given in the setting of low day-before ANC to patients with ESCRC. The benefits include higher RDI and a reduced number of clinic visits for the patient.

Full-dose chemotherapy in early stage breast cancer regardless of absolute neutrophil count and without G-CSF does not increase chemotherapy-induced febrile neutropenia

PURPOSE

Does giving full-dose adjuvant chemotherapy to patients with early stage breast cancer (ESBC) regardless of the day-before absolute neutrophil count (ANC) lead to an increased incidence of chemotherapy-induced febrile neutropenia (CIFN)? What factors may predispose patients to CIFN?

METHODS

This was a retrospective chart review conducted on all patients receiving adjuvant chemotherapy for ESBC at a mid-sized community hospital in Toronto, Ontario, Canada between September 2005 and August 2011. Day-before CBC data were collected along with other patient characteristics. CIFN was confirmed by hospital records. One hundred fifty-four patients met the inclusion criteria. Overall, 830 cycles of chemotherapy were analyzed. Univariate and multivariate logistic regression analyses were used to identify risk factors for CIFN.

RESULTS

Twenty-two episodes of CIFN were observed. There was no significant difference in day-before ANC between patients who developed CIFN relative to those who did not. The day-before ANC was <1.5 × 10(9)/L for 88 cycles of chemotherapy. ANC analyzed as a continuous variable showed that the odds ratio (OR) for CIFN was 0.97 (95 % CI 0.82-1.13, p = NS). The pseudo R (2) statistic, which is a measure of variability accounted for by a regression model, was only 0.0008, indicating that ANC explained less than 1 % of the variability in the risk of CIFN. The most significant predictor of CIFN was the chemotherapy regimen, with docetaxel (Taxotere)/cyclophosphamide demonstrating the highest risk (OR 7.1, 95 % CI 1.4-34.9, p = 0.016).

CONCLUSIONS

Full-dose adjuvant chemotherapy may be given to patients with ESBC regardless of the day-before ANC, without significantly increasing the risk of CIFN. The chemotherapy regimen is the most significant predictor for CIFN.

Five-year data and prognostic factor analysis of oxaliplatin and irinotecan combinations for advanced colorectal cancer: N9741

PURPOSE

In this report, we update survival (OS) and time-to-progression (TTP) data for the Intergroup trial N9741 after a median 5 years of follow-up by using risk-stratified and prognostic factor analyses to determine if treatment outcomes differ in specific patient subgroups.

PATIENTS AND METHODS

A total of 1,691 patients were randomly assigned to one of seven fluorouracil-, oxaliplatin-, and irinotecan-containing regimens. OS and TTP were calculated by treatment arm and baseline risk group (on the basis of WBC, performance status, number of sites of disease, and alkaline phosphatase). Multivariate prognostic factor analysis was used to assess clinical factors for their relationships to OS, TTP, response, and toxicity by using Cox and logistic regression models.

RESULTS

The observed 5-year survival with infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX) of 9.8% was better than with irinotecan plus bolus fluorouracil and leucovorin (IFL; 3.7%; P = .04) or with bolus irinotecan/oxaliplatin (IROX; 5.1%; P = .128). OS and TTP were significantly longer for FOLFOX (20.2 months and 8.9 months, respectively) than for IFL (14.6 months and 6.1 months, respectively; P < .001 for both) or for IROX (17.3 months and 6.7 months, respectively; P < .001 for both). OS differed by risk group: 20.7 months for low risk, 17.4 months for intermediate risk, and 9.4 months for high risk (P < .001). FOLFOX treatment was superior in all risk groups and was the most powerful prognostic factor for OS, TTP, response rate, and toxicity.

CONCLUSION

The 9.8% 5-year OS in patients with metastatic colorectal cancer who were treated with first-line FOLFOX sets a new benchmark. Neither baseline risk group nor any prognostic factor examined was predictive of treatment-specific outcome. However, treatment efficacy and patient longevity varied as a function of risk group.

Model-based design of chemotherapeutic regimens that account for heterogeneity in leucopoenia

Patients treated with multicycle chemotherapy can exhibit large interindividual heterogeneity of haematotoxicity. We describe how a biomathematical model of human granulopoiesis can be used to design risk-adapted dose-dense chemotherapies, leading to more similar leucopoenias in the population. Calculations were performed on a large data set for cyclophosphamide/doxorubicin/vincristine/prednisone (CHOP)-like chemotherapies for aggressive non-Hodgkin lymphoma. Age, gender, Eastern Cooperative Oncology Group performance status, lactate dehydrogenase and the degree of leucopoenia within the first therapy cycle were used to stratify patients into groups with different expected severity of leucopoenia. We estimated risk-specific bone marrow toxicities depending on the drug doses administered. These toxicities were used to derive risk-adapted therapy schedules. We determined different doses of cyclophosphamide and additional etoposide for patients treated with CHOP-14. Alternatively, the model predicted that further reductions of cycle duration were feasible in groups with low toxicity. We also used the model to identify appropriate granulocyte colony-stimulating factor (G-CSF) schedules. In conclusion, we present a method to estimate the potential of risk-specific dose adaptation of different cytotoxic drugs in order to design chemotherapy protocols that result in decreased diversity of leucopoenia between patients, to develop dose-escalation strategies in cases of low leucopoenic reaction and to determine optimal G-CSF support.

A computational model of human granulopoiesis to simulate the hematotoxic effects of multicycle polychemotherapy

Moderate intensification of conventional multicycle chemotherapy has recently been shown to improve treatment results in malignant lymphomas and might prove to be beneficial also in other malignancies. However, the feasibility of such regimens is mainly limited by their granulopoietic toxicity. To identify and quantify the basic cell kinetic mechanisms of damage and stimulation caused by cytotoxic drugs and recombinant human granulocyte colony-stimulating factor (rhG-CSF), respectively, we developed a mathematical model of human granulopoiesis that allows simulation of leukocyte concentration profiles under 10 different multicycle polychemotherapy regimens with varying drug composition, dosage, and scheduling, including rhG-CSF assistance. Clinical data on leukocyte profiles were obtained from large numbers of patients treated within several multicenter trials. Simulation studies show that the leukocyte profiles of all regimens can be appropriately fitted using one single set of assumptions and parameters for the cell kinetic effects of cytotoxic drugs and rhG-CSF. Furthermore, the model can be used to explain the interindividual heterogeneity of hematotoxicity by a differential chemosensitivity, which might be useful in drug scheduling for specific risk groups. It is demonstrated that the model can be used to design and to select new drug schedules for subsequent clinical trial testing.