Date Published: April 3, 2018
Publisher: Public Library of Science
Author(s): Constanza Maximiano, Iker López, Cristina Martín, Luis Zugazabeitia, Juan L. Martí-Ciriquián, Miguel A. Núñez, Jorge Contreras, Michael Herdman, Susana Traseira, Mariano Provencio, Qinhong Zhang.
There have been few large-scale, real world studies in Spain to assess change in pain and quality of life (QOL) outcomes in cancer patients with moderate to severe pain. This study aimed to assess changes on both outcomes after 3 months of usual care and to investigate factors associated with change in QoL.
Large, multi-centre, observational study in patients with lung, head and neck, colorectal or breast cancer experiencing a first episode of moderate to severe pain while attending one of the participating centres. QoL was assessed using the EuroQol-5D questionnaire and pain using the Brief Pain Inventory (BPI). Instruments were administered at baseline and after 3 months of follow up. Multivariate analyses were used to assess the impact of treatment factors, demographic and clinical variables, pain and other symptoms on QoL scores.
1711 patients were included for analysis. After 3 months of usual care, a significant improvement was observed in pain and QoL in all four cancer groups (p<0.001). Effect sizes were medium to large on the BPI and EQ-5D Index and Visual Analogue Scale (VAS). Improvements were seen on the majority of EQ-5D dimensions in all patient groups, though breast cancer patients showed the largest gains. Poorer baseline performance status (ECOG) and the presence of anxiety/depression were associated with significantly poorer QOL outcomes. Improvements in BPI pain scores were associated with improved QoL. In the four cancer types studied, pain and QoL outcomes improved considerably after 3 months of usual care. Improvements in pain made a substantial contribution to QoL gains whilst the presence of anxiety and depression and poor baseline performance status significantly constrained improvement.
Pain is a common and burdensome symptom in cancer patients  with data indicating that 50%–90% will require treatment for pain during the course of their disease . Opioids are recommended for the management of moderate/severe cancer pain by the World Health Organization and current guidelines [3, 4] and are recognized as the treatment of choice in these patients . Despite the importance of adequate pain management, however, studies show that there is substantial undertreatment of cancer pain [6 Deandrea]. One of the causes for this undertreatment could be the underuse of pain scales by health professionals in clinical practice.
The demographic, clinical and treatment characteristics of the study population included for the current analysis are shown in Table 1. In all cancer types, the majority of patients were in ECOG 0 or 1 (range from 63.2% in colorectal cancer to 75.2% in head and neck cancer). Almost 70% of patients were on chemotherapy, which was largely palliative, except in head and neck cancer (72.7% curative).
In this exploratory study of outcomes in cancer patients treated in usual clinical practice in Spain, we observed substantial improvements in pain and QOL in the four cancer types studied. In terms of results on the pain measure (BPI), patients in all 4 groups showed similar magnitudes of improvement on the severity and interference sub-scales. The smallest improvement on the severity sub-scale was seen in the colorectal group, though the difference was small (change of 2.7 vs a mean change of 3.1 in the other three groups). All of the changes correspond to large effect sizes, indicating substantial improvement in pain in all four groups. As regards QOL, breast cancer patients showed the biggest improvement on the EQ-5D Index, followed by head and neck, colorectal, and lung cancer patients. Interestingly, the order was not the same on the EQ-5D VAS, where head and neck patients showed the biggest gains, followed by lung, colorectal, and breast cancer patients.