[Risk of cancer in patients following chronic dialysis and kidney graft]

Onco-nephrology: Physicians' Expectations About a New Subspecialty

INTRODUCTION

Renal events are common in cancer patients and malignancy is a prevalent complication in both patients transplanted and under kidney replacement therapy (KRT). In recent years, onco-nephrology has been developed as a subspecialty whose scope has not been well established yet. The aim of our study was to assess resident and senior physicians' knowledge and expectations about onco-nephrology.

METHODS AND MATERIALS

Two anonymous self-administered online questionnaires were developed by a multidisciplinary team and distributed to French residents and senior physicians.

RESULTS

Two hundred twenty-eight physicians answered the survey, including 128 (56%) nephrologists, of which 98 (43%) were senior physicians and 130 (57%) were residents. Nephrologists rated their confidence in their ability to face onco-nephrological situation at 6/10 (interquartile range (IQR) 4.0-7.0) and oncologists at 6.0/10 (5.0-7.0). Managing cancer drugs in patients on KRT or in transplanted patients and discussion about introducing dialysis in cancer patients were designated as the most challenging topics. Asking if they had received appropriate learning, residents' median agreement was ranked at 3.0/10 (2.0-4.0). Forty-six percent of the respondents considered available resources as not appropriate. Specialized onco-nephrology consultations were accessible for 21% of the respondents. Finally, respondents thought there is a strong need for a national working group (8.3/10) with 87% of them expecting new reliable guidelines.

CONCLUSION

The present survey revealed physicians' expectations about onco-nephrology implementation in France. An appropriate answer could be the creation of a national working group. Therefore, GRIFON (Groupe de Recherche Interdisciplinaire en OncoNéphrologie) has recently been created.

Is there different risk of cancer among end-stage renal disease patients undergoing hemodialysis and peritoneal dialysis?

Cancer is a global issue in recent decade. Despite this alarming increase in the incidence of cancer, to date, whether the risk of developing cancer differs among peritoneal dialysis (PD) and hemodialysis (HD) patients is still uncertain. In this retrospective cohort study, data were obtained from the National Health Insurance Research Database of Taiwan, which provides coverage to almost 99% of the nation's population. After matching, a total of 4491 (or 3369) incident PD patients and 8982 (or 6738) incident HD patients between 2000 and 2009 were enrolled from the database. In addition, 22,455 (or 16,845) nondialysis patients were selected as a control group. The patients were monitored for the occurrence of cancer until 2010, and their data were analyzed using several different models. In general, the results showed that the risks of hepatocellular, kidney, bladder, extra kidney/bladder urinary tract, and thyroid cancers were higher in dialysis patients. We also compared the risk of cancer between two dialysis groups by using the HD patients as the reference group. The result showed that there is no significant different for each cancer risk between two dialysis groups. In conclusion, dialysis patients had a higher risk of certain types of cancer than those in the nonuremia group. However, there was no significant difference in the cancer risk between the two dialysis groups when compared directly.

Relationship Between Vitamin D Blood Levels and Cancer Development in Renal Transplant Patients: A Case-Control Study

BACKGROUND

Malignancy is one of the most common long-term complications in renal transplant patients, often related to immunosuppressive treatment although other factors could be considered. Vitamin D plays an important role in reducing cancer risk. After kidney transplantation (KT), 25-hydroxyvitamin D (25OH-D, or calcidiol) insufficiency concerns >85%. The main aim of the present study was to determine the relationship between calcidiol blood levels and cancer development in KT recipients.

METHODS

This was a retrospective observational case-control study including patients who received transplants in our hospital from 2003 to 2009 with a follow-up period to 2015. A total of 738 patients were included; 94 of them developed malignancy process, 80 of whose tumor data were analyzed in the cancer group, and the rest composed the control group. At the moment of cancer presentation, age, sex, primary kidney disease, time after surgery, immunosuppressant schedule, and 25OH-D blood levels were collected.

RESULTS

The mean patient age was 57 years. The percentages of man and women were 59.5% and 41.5%. The predominant etiology of kidney disease was chronic glomerulonephritis in 31.9%. There were no significant differences between sex, primary kidney disease, immunosuppressant schedule, or incidence of neoplasm in each group of patients. There were no significant differences in 25OH-D blood levels. The incidence of cancer was 7.1%-13.7% per year. The mean time between the graft surgery and the event was 5.6 years.

CONCLUSIONS

In patients with functioning KT, we found no correlation between blood levels of calcidiol and the incidence of cancer.

Melatonin rhythms in renal transplant recipients with sleep-wake disturbances

We assessed salivary melatonin levels in renal transplant (RTx) recipients who participated in a randomised, multicentre wait-list controlled trial on the effect of bright light therapy on their sleep and circadian rhythms. A large proportion of RTx recipients in our cohort had unexpectedly low melatonin values, which precluded calculation of the dim-light melatonin onset (DLMO) as a circadian marker. Thus, the aim of this post hoc analysis was to describe the melatonin profile of home-dwelling RTx recipients diagnosed with sleep-wake disturbances (SWDs). The participants were characterised by means of sleep questionnaires, validated psychometric instruments [Pittsburgh sleep quality Index (PSQI), Epworth sleepiness scale (ESS), Morningness-Eveningness Questionnaire (MEQ) and Depression, Anxiety and Stress Scale (DASS)] in addition to melatonin assay in saliva. Data were analysed with descriptive statistics and group comparisons made with appropriate post hoc tests. RTx recipients [n = 29 (aged 54.83 ± 13.73, transplanted 10.62 ± 6.84 years ago)] were retrospectively grouped into two groups: RTx recipients whose dim light melatonin onset (DLMO) could be calculated (n = 11) and those whose DLMO could not be calculated (n = 18). RTx recipients having a measurable DLMO had a number of differences from those without DLMO: they were younger [46.4 ± 14.9 compared to 60.0 ± 10.3 (p = .007)], had higher haemoglobin values [135.36 ± 12.01 versus 122.82 ± 11.56 (p = .01)], less anxiety [4 (0;8) versus 12 (6.5;14) (p = .021)] and a better overall sense of coherence [SOC Score: 71.09 ± 12.78 versus 56.28 ± 15.48 (p = 0.013)]. These results suggest that RTx recipients whose DLMO could be calculated have less health impairments, underlying the relevance of a stable circadian system.