Systemic treatment with organ failure

For patients with lung cancer, choices of systemic therapy are informed by clinical research. These guide the patient and clinician as to the gold standard options when facing their disease. However many patients seen day to day in the clinic are not eligible for clinical trials due to one factor or another, and therefore the applicability of standard of care options has a less solid evidence base. In a recent analysis of 528 newly diagnosed stage 4 NSCLC patients seen in consultation by medical oncologists, only 55% received systemic treatment 1. Further, when simple and limited generic clinical trial inclusion criteria were applied to these patients, only 27% would have been 'trial eligible' 2. In a review of selected recent practice changing chemotherapy, targeted therapy and immunotherapy trials, patients with significant renal impairment, hepatic impairment or cardiac impairment would have been excluded 3-6. Therefore how should clinicians and patients approach making decisions about systemic therapy in the presence of organ failure, given the lack of available evidence? This abstract seeks to provide guidance on a reasonable approach to patients with lung cancer and organ failure. These issues should be discussed in a multi-disciplinary format, with specific interaction with specialists related to the particular organ failure (nephrology, hepatology, cardiology etc.), in addition to a specialist oncology pharmacist if the decision is made to proceed with therapy. Patients should be fully informed regarding relative benefits and harms from therapy, the consequences of declining therapy, and that proceeding with treatment will almost certainly not be based on level one evidence. Consideration should be given to early palliative care specialist input, and advance care planning. Understanding the cause and prognosis of the organ failure is self-evidently important. This abstract restricts discussion to patients with pre-existing organ failure, rather than organ failure secondary to the malignancy. In a recent review of clinical indicators of 6-month mortality in advanced non-cancer illnesses, Salpeter and colleagues evaluated heart failure, dementia, geriatric failure-to-thrive syndrome, hepatic cirrhosis, chronic obstructive pulmonary disease and end-stage renal disease. This list represented approximately 70% of the non-cancer diagnoses on admission to hospice 7. Clearly not all patients with these conditions die within 6 months, and the authors identified common and disease specific prognostic indicators, including poor PS, malnutrition, comorbid illness and organ dysfunction. In the cancer clinic, the clinician must understand the natural course of the organ failure pathology. For patients with liver, kidney or heart failure who may be waiting for organ transplantation, the diagnosis of lung cancer makes them ineligible for the transplant program. Regarding prognosis of advanced organ failure, the United States Renal Data System (USRDS) Annual Report for patients receiving hemodialysis for end-stage renal disease, describes 3-year survival as 52%, and 61% for patients receiving peritoneal dialysis. The risk of death is particularly high in the first year of hemodialysis, with rates reported up to 25%. The Canadian Organ Replacement Register Annual Report describes a 5-year survival for patients on dialysis of approximately 43% (www.cihi.ca/corr ). For patients with end-stage heart failure, the 1-year survival is approximately 50% 8, which is not dramatically different to patients with stage 4 NSCLC receiving 1st line chemotherapy. The prognosis of patients with liver cirrhosis is variable, depending on severity, etiology and the presence or absence of complications. The MELD score (Model for End-Stage Liver Disease) is used to assess the severity of chronic liver disease 9, as an alternative to the Child-Pugh scoring system. Salpeter et al reported patients with decompensated liver failure (the presence of complications of cirrhosis) may have a median survival <6 months if associated with high MELD scores. An understanding of competing morbidities therefore clearly plays an important role in understanding the role systemic therapy plays in lung cancer. In assessing the need for adjuvant chemotherapy in patients with early stage disease, for patients with organ failure it is highly likely that any benefit from chemotherapy (approximately 5%) will be outweighed by the competing risks of the comorbid condition. After assessing patients with lung cancer, in the multi-disciplinary context and taking into account the issues discussed, the decision may still be to proceed with therapy. This should be on the understanding of the relative lack of data, and then a choice of regimen based on an understanding of the drug metabolism, with appropriate dose adjustments after dialogue with an oncology pharmacist. Table 1 outlines common lung cancer drugs and their route of elimination, and recommendations on use in renal or hepatic impairment. For patients receiving dialysis, there is variation in advice as to timing of administration relative to dialysis. This information and tabular information is taken from product monographs and selected references 10,11. Data on efficacy for these drugs in these scenarios is largely limited to case reports. In conclusion, lung cancer patients with organ failure represent a population excluded from clinical trials and with a limited evidence base. The competing morbidity and mortality significantly mitigate against potential benefits from anti-cancer systemic therapy. The newer generations of targeted therapies and immunotherapies may be easier to deliver, but again limited data exists. Clinicians should discuss these cases in a multi-disciplinary environment, and early intervention from palliative care specialists may be particularly appropriate. (Table Presented).