As cancer incidence increases with age, with 30% of cancers in 2005 occurring in patients over 75 years 1 , the burden of cancer in the elderly is rising and has an impact on the cost and organization of care. Given the size of the elderly population and this increased incidence of cancers, it is important to optimise the way in which elderly cancer patients are cared for and their quality-of-life. Cancers are often diagnosed late in the elderly 2 3 . Potential explanations for this are, among others, distance from care facilities, loss of autonomy and the fact that the elderly tend to miss screening measures. The general practitioner (GP) has a central role in the organisation of care provision: it is s/he who decides where to refer the patient 4 , and the care provided may vary in quality according to the facility selected for referral 5 . For elderly people, the GP's role is particularly important, since elderly patients are generally more dependent than younger patients 4 5 . Once the diagnosis of cancer is established in clinical practice, numerous factors can influence the decision as to how elderly cancer patients are cared for. These factors include age, acceptability of the treatment by the patient or the patient's family, mental status, the presence of disability, the facility to which the patient might be referred, and the attitude of the physician 6 7 .

The main aim of this study was to describe the factors influencing GPs in South-West France (Aquitaine) in their decisions whether or not to refer elderly cancer patients to oncology teams, using a cross sectional design. The detailed objectives of the study were to: 1) estimate the proportion of GPs who refer their patients according to cancer stage (early or advanced), 2) identify factors associated with this decision among influential elements and individual GP characteristics, and 3) use two clinical case vignettes to identify the factors influencing GPs in clinical situations in their decision to refer an elderly patient presenting with cancer to specialised care.

In our study, approximately half of the GPs declared that they always refer elderly cancer patients to a cancer team (this was slightly more frequent for early stages than for advanced disease). More than three quarters of referring and non-referring GPs reported being influenced by the five following patients-linked factors: 1) wish or reluctance on the part of the patient; 2) wish of the family if present; 3) presence or absence of serious comorbidity; 4) unsuitability of conducting invasive investigations; and 5) the degree of mental and physical autonomy. Three quarters or more of the GPs were influenced by two disease-linked factors, the seriousness of the cancer symptoms and expected side effects and tolerance of treatment. Finally, being used to collaborating with specialist cancer teams was the only organisational element reported to be influential by more than 75% of the GPs. With regard to the two specific cancer cases presented in clinical case vignettes, the GPs did not have the same approach for the two patients, nor when compared to the general referral situation. Confronted with a case of prostate cancer, the GPs tended to refer the patient to a specialist (75%), whereas when faced with a sigmoid colon cancer, 45% of GPs reported that they would refer to a specialist and 40% to an oncologist. For both these types of cancer, the seriousness of the symptoms appears to influence GPs the most. Regardless of the stage of the cancer, organisation difficulties were an independent factor influencing the GP's decision whether or not to refer elderly patients.

In studies reported in the literature and conducted in other regions in France and in Canada 10 12 , higher referral rates of elderly patients presenting with cancer have been reported according to patient's age 12 and to stages of the disease 10 . Our referral rates are slightly lower in the general situation, but we have similar high referral rates for both clinical vignettes. Overall, slightly more GPs declared that they "always refer" for early stages than for advanced disease which is similar to results previously reported 10 . In Canada, as in France today, patients encountering a health problem consult in the first instance the family practitioner (GP) who decides if referral to a specialist is required. It is possible that in the present study the figure for referral is underestimated on account of the absence in France for a clear definition of a "team of cancer specialists", so that the GPs may not have included specialists practising oncology under the term.

In terms of the factors influencing GPs' referral decisions, we found the same factors to be cited in majority (patient's wishes and tumour-related factors) as observed previously 10 12 . When independent factors associated with the decision to "always" refer an elderly patient to a cancer team for early stages of the disease are considered, GPs reporting being influenced by the anatomical localisation of the cancer reported referred their patients less often. In the limited literature available, the anatomical localisation has never been documented as a factor influencing GPs' decisions. However, this factor seems likely to play a part in decisions on the way a cancer patient is to be cared for, and this aspect was confirmed in this study. In particular, our results show that the GPs did not refer patients in the same way in the general situation (responses to questionnaire Section B) and in the two clinical situations proposed. Another decisional factor found, irrespective of disease extension, was the difficulty involved in organising care. This factor is also found in another two studies conducted on a sample of GPs where organisational difficulties were found to influence decisions 10 12 . This has also been observed in studies conducted among elderly breast and colon cancer patients where the patients reported preferring to receive care close to their homes 13 14 . Indeed, cancer care that is often complex and requires frequent consultations may be difficult to organise for elderly patients living at a distance from the specialised cancer centres. In this context, the GP may choose to refer a patient to a closer facility such as, a geriatric or medical ward 6 . Despite this, the practice setting (urban or rural) was not found as a significant factor in any of the models in the present study. For advanced cancer, GPs reporting that they "did not always refer" their patients were those not having attended courses in oncology, and those influenced by the chronological age of their patients, the stage of advancement of the disease, or organisational difficulties for care. For this group, age itself was a determining factor of the referral decision. This association has not been documented in the literature up until now. This difference may not have been observed in the Canadian study as it was performed some time ago and in a different health system 10 . In the French study, the stage was not taken into account when studying referral decisions 12 . Oncology training was found to increase referral rates in our study, but we did not observe an association with geriatric training that has previously been reported in the literature as decreasing referral rates 10 12 .

The GPs did not refer their patients to the same specialists in the two clinical case vignettes. For prostate cancer patients, GPs referred their patients to a urological specialist. For patients with colon cancer, GPs referred their patients to a gastro-enterologist or to an oncologist. Specialists' attitudes towards oncogeriatrics and established collaboration relationships can have an important impact on the initial management of patients 15 .

Finally, there are two main limitations to this study to keep in mind when interpreting results. The first relates to the type of survey, with this being a postal survey conducted among GPs in the South-West region of France, Aquitaine. After two reminders, an acceptable response rate for this type of study was obtained (30%). At first regard, this may seem low and indicate a selection bias, but since only 50% of graduated doctors are thought to be in general practice in France 16 , probably only 50% of the GPs listed in the regional database we used to generate our participant list were actually concerned by the study. Kurtz et al 12 showed a higher GP response rate but this difference can be explained by the different types of questionnaire (they did not present clinical case vignettes) and they employed a more direct regional communication method to obtain GP responses. In our group of respondents, there were slightly more males and GPs with a rural practice than in the regional GP database. An explanation could be that these GPs see more elderly patients so they were more interested in participating in the study.

The second limitation concerns the fact that the clinical cases vignettes covered two specific disease localisations and the GPs were probably influenced by the prognosis for these specific cancers.

Overall, our results indicate that it is still necessary to raise awareness among physicians so that all patients, regardless of age, stage of disease or anatomical localisation of the cancer, be seen by a team of oncologists in order for a decision suited to the patient to be reached.

Three specific elements influencing GPs' decisions for the referral of elderly patients with cancer to a cancer team should be highlighted in our results as the focus for future research or interventions. The organisational difficulties encountered by GPs highlight the need for further studies to comprehend the nature of these difficulties and to suggest solutions suited to the local setting. Another factor identified concerns the lack of training in oncology that should be developed in the future. The role of specialist physicians is likewise important in the promotion of oncogeriatrics among GPs.

GP: General Practitioners; CI: Confidence Interval; sd: standard deviation

The authors declare that they have no competing interests.

FD: conceived of the study, participated in its design and coordination, performed the statistical analysis and drafted the manuscript; EM: helped with acquisition of data, interpretation of data and revising the manuscript; MF: participated in interpretation of data and revising the manuscript; MR: participated in interpretation of data and revising the manuscript; JLD: participated in interpretation of data and revising the manuscript; PM: participated in interpretation of data and revising the manuscript; PS: participated in interpretation of data and revising the manuscript; AJS: participated in interpretation of data and revising the manuscript; SMP: conceived of the study, participated in its design and coordination and revising statistical analysis and the manuscript. All authors read and approved the final draft.