Single-Agent Irinotecan as Second-Line Weekly Chemotherapy in Elderly Patients with Advanced Colorectal Cancer

An appraisal of emerging second line therapies for metastatic colorectal cancer

INTRODUCTION

Despite a significant improvement in overall survival over the last 15 years, colorectal cancer remains a major public health problem worldwide. Much effort has been made to develop an optimal choice of first-line treatments, but after progression the therapeutic possibilities and the criteria for choice are different.

AREAS COVERED

The purpose of this literature review is to discuss the different possibilities of second-line treatment and to specify the criteria for choice. Biological subgroups requiring specific therapeutic decisions will be described. We conducted a systematic review for randomized controlled trials published since 1995. A non-exhaustive review of published phase II studies, cohort studies, and international guidelines was also given and future leads were discussed.

EXPERT OPINION

Some choices of second-line treatments are a direct result of the option chosen in the first line. Others are necessary because of the biological specificity of the tumor: immunotherapy for tumors with microsatellite instability, or the combination encorafenib cetuximab for mutated BRAF-V600E tumors. In many other circumstances, there are several options that require extensive involvement of multidisciplinary boards and the patient in the final therapeutic decision.

An update on the management of metastatic colorectal cancer in the elderly

SUMMARY 

The availability of new chemotherapeutic and targeted agents has changed the life expectancy of patients with metastatic colorectal cancer thanks to the possibility of sequentially administering fluoropyrimidines combined with irinotecan and oxaliplatin plus monoclonal antibodies. This approach is seldom feasible in the elderly, especially because of the poor tolerability of some agents. Frail patients should only receive palliative treatment. Oppositely, fit elderly patients can be treated with more aggressive therapies, similarly to the younger ones. What is not sufficiently known is how to manage the elderly categorized as intermediate. In the coming years, it appears necessary how to accurately differentiate the elderly through a comprehensive geriatric assessment performed with validated scales and uniformed criteria simpler than those currently available.

Relative effectiveness and safety of chemotherapy in elderly and nonelderly patients with stage III colon cancer: a systematic review

BACKGROUND

Chemotherapy effectiveness in clinical practice may differ from the efficacy demonstrated in clinical trials, particularly among populations underrepresented in clinical trials, such as elderly patients with cancer. This review aims to examine the relative effectiveness of chemotherapy for stage III colon cancer in elderly versus nonelderly patients.

METHODS

A systematic literature review was conducted using the Agency for Healthcare Research and Quality approach. Literature searches were performed in Medline and Evidence-Based Medicine Reviews databases. Chemotherapy regimens approved for stage III colon cancer were reviewed. Four effectiveness and 15 safety outcomes were extracted.

RESULTS

From 708 identified articles, 25 articles provided data on the relative effectiveness and safety of chemotherapy among elderly versus nonelderly patients. Four of 14 studies showed lower overall survival treatment effects, whereas one of five and one of four studies indicated more favorable treatment effects for time to progression and overall response rate. Grade 3 or 4 adverse events were higher among elderly patients for cardiac disorder (2/5 studies), leukopenia (1/5), neutropenia (4/16), thrombocytopenia (2/13), febrile neutropenia (1/4), infection (2/10), dehydration (2/6), diarrhea (6/20), and fatigue (6/13). Grade 3 or 4 adverse events were lower for neutropenia (2/16 studies), nausea/vomiting (1/16), and neuropathy (1/9).

CONCLUSION

The majority of the evidence suggests that chemotherapy has similar relative effectiveness and safety for patients >65 years of age versus younger patients with stage III colon cancer. When differences are reported, treatment effects are more often worse among the elderly. This review suggests that without other reasons for withholding treatment, elderly patients should receive chemotherapy as often as nonelderly patients.

Oxaliplatin-based chemotherapy in the treatment of elderly patients with metastatic colorectal cancer (CRC)

Elderly patients constitute a subpopulation with special clinical features that differ from those of the general population and are under-represented in clinical trials. We retrospectively analyzed the toxicity and efficacy of oxaliplatin-based chemotherapy in the treatment of elderly patients affected by metastatic (m) CRC. Seventy-five consecutive patients aged 65-75 years (median age 71 years), 51 males and 24 females, with mCRC and measurable disease, were analyzed. The primary site of metastases was the liver (38.6% of patients). The majority of patients had a performance status (PS) according to the Eastern Cooperative Oncology Group (ECOG) PS before treatment of 0-1 (96%). The overall response rate was 57.3%, median progression-free survival was 7 months and median overall survival was 27 months. The main hematological and extra-hematological toxicities (grade 3 or 4) were neutropenia (20.0%), and neurological toxicity or diarrhea (6.7%), respectively. No toxic death occurred. Oxaliplatin-based chemotherapy maintains its efficacy, and safety in elderly patients with mCRC and good PS. This regimen should be considered in the treatment of this particular setting of patients.

FOLFOX4 in the treatment of metastatic colorectal cancer in elderly patients: a prospective study

Elderly patients constitute a subpopulation with special characteristics that differ from those of the general population and have been under-represented in clinical trials. We, prospectively, analyzed the toxicity and efficacy of the original FOLFOX4-regimen in the treatment of elderly patients affected by metastatic (m) colorectal cancer (CRC). Thirty-six consecutive patients aged 67-82 years (median age 72 years), 22 males and 14 females, with mCRC and measurable disease, were enrolled in the study. The primary site of metastases was the liver (36.1% of patients). The median ECOG Performance Status (PS) was 1. The main hematological and extra-hematological (grade 3 or 4) toxicities were neutropenia (38.9%) and neurological (13.9%), respectively. A total of 36 patients, aged 67-82 years were included. Twenty-two and 14 patients were male and female, respectively. The median age was 72 years (range 67-82). The primary site of metastases was the liver (36.1% of patients). The median ECOG Performance Status (PS) was 1. The overall response rate (ORR) was 44.4% and similar to original study. Median progression-free survival (PFS) was 7.5 months and median overall survival (OS) was 16 months. The main hematological and extra-hematological (grade 3 or 4) toxicities were neutropenia (38.9%) and neurological (13.9%), respectively. Tolerability, however, was manageable and no toxic death occurred. FOLFOX4-regimen maintains its efficacy, and safety ratio in elderly patients with mCRC and good performance status. It would be considered the treatment of choice in the treatment of this particular setting of patients.

Treatment of Fluorouracil-Refractory Patients With Liver Metastases From Colorectal Cancer by Using Yttrium-90 Resin Microspheres Plus Concomitant Systemic Irinotecan Chemotherapy

Purpose

Liver metastases are the principal cause of death in patients with advanced colorectal cancer (CRC). Irinotecan is a chemotherapeutic agent used in the treatment of CRC and has demonstrated synergistic potential when used with radiation. Radioembolization with yttrium-90 microspheres has demonstrated increased response and survival rates when given with fluorouracil chemotherapy. This study's goal was to evaluate the maximum-tolerated dose of concomitant irinotecan and radioembolization in fluorouracil-refractory patients with CRC hepatic metastases.

Patients and Methods

Twenty-five irinotecan-naïve patients who had experienced relapse after previous chemotherapy were enrolled onto three dose-escalating groups. Irinotecan was administered at 50, 75, or 100 mg/m2 on days 1 and 8 of a 3-week cycle for the first two cycles, and full irinotecan doses (ie, 100 mg/m2) were administered during cycles 3 to 9. Radioembolization was administered during the first chemotherapy cycle.

Results

Most patients experienced acute, self-limiting abdominal pain and nausea. Mild lethargy and anorexia were common. Grades 3 to 4 events were seen in three of six patients at 50 mg/m2 (obstructive jaundice, thrombocytopenia, diarrhea), in five of 13 patients at 75 mg/m2 (neutropenia, leukopenia, thrombocytopenia, elevated alkaline phosphatase, abdominal pain, ascites, fatigue) and in four of six patients at 100 mg/m2 (diarrhea, deep vein thrombosis, constipation, leukopenia). Eleven (48%) of 23 patients had a partial response, and nine patients (39%) had stable disease. The median progression-free survival was 6.0 months; the median survival was 12.2 months.

Conclusion

Concomitant use of radioembolization plus irinotecan did not reach a maximum-tolerated dose. The recommended dose of irinotecan in this setting is 100 mg/m2 on days 1 and 8 of a 3-week cycle.

Chemotherapy options and outcomes in older adult patients with colorectal cancer

The majority of patients with colorectal cancer (CRC) are >/=65 years of age, yet older patients with CRC remain under-represented in clinical trials. Older adult patients may be more likely than younger patients to experience chemotherapy-related toxicities due to factors such as existing comorbidities, incompatibility of chemotherapy with other medications, and age-related reduction in the detoxification and elimination potential of the liver and kidneys. However, the older patient group are a heterogeneous population. The available data on treatment of older patients with CRC indicate that fit older adult patients have the potential to derive the same benefit as do younger patients. A comprehensive geriatric assessment can help to identify patients most likely to benefit from standard treatment. In this review, we will evaluate the chemotherapy regimens investigated in older adult patients with CRC, and how the safety profiles and efficacy of chemotherapy in the older adult compare with those observed in younger patients.

Review article: benefits and risks of chemotherapy in elderly patients with metastatic colorectal cancer

BACKGROUND

Although metastatic colorectal cancer (mCRC) is largely a disease of older individuals, our understanding of disease processes and their optimal treatment has been gained through trials with populations largely confined to younger individuals.

AIM

To identify through a review issues specific to geriatric patients with mCRC (physiological changes associated with aging, burden of coexisting illnesses, altered drug pharmacokinetics and functional impairment) and assess challenges to elderly patients posed by malignancy and exposure to cytotoxic medication.

METHODS

Our literature search for indexed articles published between 2000 and May 2008 employed terms including irinotecan, oxaliplatin, elderly, mCRC, targeted agents and biologicals.

RESULTS

Underrepresentation of older patients in clinical trials makes it difficult to extrapolate findings to older age groups. However, some trials have demonstrated that elderly patients can achieve survival benefits and toxicity comparable to younger patients, although dosage modifications may be required.

CONCLUSIONS

Currently, benefits with pharmacological therapy are suggested but not proven in the elderly population. Although concurrent illnesses and disabilities can complicate treatment decision making, chronological age alone should not disqualify these patients with mCRC from receiving optimal treatment similar to that offered to their younger cohorts.

Irinotecan in the treatment of elderly patients with advanced colorectal cancer

Irinotecan is an active drug in the first and subsequent lines of chemotherapy for patients with advanced colorectal cancer. Frequently, the elderly patients are excluded from receiving irinotecan alone or in combination, and on many occasions these patients receive an initial reduced dose of this drug. This revision has been focused in the role of irinotecan in elderly patients.

MATERIAL AND METHODS

Data from pharmacokinetic studies, comparative analysis of prospective trials according to age and prospective studies with irinotecan alone or irinotecan-combinations in the elderly have been revised and put into context.

RESULTS

Either pharmacokinetic and clinical data suggest that fit elderly patients may tolerate irinotecan as well as the younger population. Response rate and survival achieved in elderly patients with irinotecan combinations seem to be equivalent to that obtained in younger patients.

CONCLUSION

Elderly patients with advanced colorectal cancer should be carefully evaluated in order to be classified as fit or not fit through a comprehensive geriatric assessment. For the group of fit elderly patients, irinotecan may be used as in the younger population.

Role of chemotherapy and novel biological agents in the treatment of elderly patients with colorectal cancer

Patients older than 65 years are the fastest growing segment of the cancer population. It is estimated that within 20 years over 75% of cases and 85% of deaths from colorectal cancer (CRC) will be in this setting. Concerns about cancer treatment in the elderly relate to comorbidities, which increase proportionally with age, physiological changes associated with aging which may influence drug metabolism and toxicity, and diminishing life expectancy, which particularly impacts decisions surrounding the benefits of adjuvant therapies. Over the last 10 years, significant improvements in the treatment of advanced CRC with combination therapy have been made. The randomized trials which have defined these improvements did not exclude elderly patients. However, the median age of patients in these trials has generally been approximately 60 years. Thus, it appears that some degree of selection is involved with younger and presumably fitter patients being the subjects in most of the pivotal trials. The availability of new molecularly targeted agents and newly improved existing agents has expanded the range of treatment options available. This variety gives greater flexibility in dealing with different subsets of patients, such as the elderly. However, some fit elderly patients seem to tolerate combination therapy reasonably well, while studies on unfit elderly subjects are needed.

Current treatment strategies in elderly patients with metastatic colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers in the Western world, with > 500,000 new cases diagnosed each year. One of the strongest risk factors for colon cancer is age. The incidence rates rise from 10 in 100,000 at age 40-45 years to 300 in 100,000 at age 75-80 years, with the median age at diagnosis of CRC being 71 years. With the general demographic shift toward an aging population, the number of people aged > 65 years is expected to increase. This article reviews the development of treatment for elderly patients with metastatic CRC, from single-agent fluoropyrimidines to combination therapies.

International Society of Geriatric Oncology Chemotherapy Taskforce: evaluation of chemotherapy in older patients--an analysis of the medical literature

The elderly comprise the majority of patients with cancer and are the recipients of the greatest amount of chemotherapy. Unfortunately, there is a lack of data to make evidence-based decisions with regard to chemotherapy. This is due to the minimal participation of older patients in clinical trials and that trials have not systematically evaluated chemotherapy. This article reviews the available information with regard to chemotherapy and aging provided by a task force of the International Society of Geriatric Oncology (SIOG). Due to the lack of prospective data, the conclusions and recommendations made are a consensus of the participants. Extrapolation of data from younger to older patients is necessary, particularly to those patients older than 80 years, for which data is almost entirely lacking. The classes of drugs reviewed include alkylators, antimetabolites, anthracyclines, taxanes, camptothecins, and epipodophyllotoxins. Clinical trials need to incorporate an analysis of chemotherapy in terms of the pharmacokinetic and pharmacodynamic effects of aging. In addition, data already accumulated need to be reanalyzed by age to aid in the management of the older cancer patient.