Why targeted therapies are necessary for systemic lupus erythematosus

Systemic lupus erythematosus (SLE) continues to have important morbidity and accelerated mortality despite therapeutic advances. Targeted therapies offer the possibility of improved efficacy with fewer side effects. Current management strategies rely heavily on nonspecific immunosuppressive agents. Prednisone, in particular, is responsible for a considerable burden of later organ damage. There are a multitude of diverse mechanisms of disease activity, immunogenic abnormalities and clinical manifestations to take into consideration in SLE. Many targeted agents with robust mechanistic preclinical data and promising early phase studies have ultimately been disappointing in phase III, randomized, controlled studies. Recent efforts have focused on B-cell therapies, in particular given the success of belimumab in clinical trials, with limited success. We remain optimistic regarding other specific therapies being evaluated, including interferon-alpha blockade. It is likely that in SLE, given the heterogeneity of the population involved, precision medicine is needed, rather than expecting that any single biologic will be universally effective.

Ribosomal P antibody: 30 years on the road

The identity of the protein antigens targeted by anti-cytoplasmic antibodies in lupus was discovered 30 years ago. These antigens are three acidic ribosomal phosphoproteins, P0, P1, and P2. Precise identification of the shared epitope on these three proteins enabled sensitive and specific immunoassays to be developed. Anti-P antibodies are highly specific for systemic lupus erythematosus (SLE) and occur in 15%–35% of patients, depending on ethnicity as well as the age of onset. Increased frequencies of detection of anti-P have been reported in childhood SLE as well as in neuropsychiatric, renal, and hepatic disease. While longitudinal studies by the Systemic Lupus International Collaborating Clinics (SLICC) consortium supported the association of anti-P with neuropsychiatric lupus, the predictive value of antibody determination remains controversial. This is likely explained by the heterogeneity of neuropsychiatric lupus as well as by the different methodologies used for assay. A number of experimental studies have suggested a direct pathogenic role for anti-P antibodies in brain disease. Findings include cross reactivity between anti-P and a neuronal surface antigen, which was detected in areas of the brain involved in memory, cognition, and emotion. Direct injection of anti-P antibodies into the brains of rodents was also associated with abnormal electrical activity and behavioral disturbances. Taken together, research over the last 30 years has established anti-P antibodies as a useful diagnostic marker of SLE and at least a subset of patients with neuropsychiatric disease. Further research is required to fine tune the association of anti-P with clinical manifestations and establish beyond high probability a pathophysiologic role for the antibodies.

Abstract S2-03: Does BRCA status affect outcome in young breast cancer patients? Results from the prospective study of outcomes in sporadic and hereditary breast cancer (POSH)

Background

Germline mutations in BRCA1/2 account for ∼3% of breast cancer cases but >10% of young patients who present with triple negative (TN) breast cancer. Young age at diagnosis is also associated with an increased risk of recurrence and inferior survival compared to older patients. Numerous publications describe an increased incidence of adverse biological features in tumours from young breast cancer patients; however it is unclear whether these fully explain the poor outcome.

The effect of carrying a BRCA1/2 mutation on the prognosis of breast cancer remains controversial with retrospective studies reporting better, similar and worse outcomes for mutation carriers compared to patients with sporadic tumours. BRCA carriers could feasibly have enhanced or reduced sensitivity to certain chemotherapeutics; however retrospective studies are problematic due to missing data and biased ascertainment. POSH is multicentre prospective observational cohort study designed to investigate factors which affect prognosis in young breast cancer patients (Copson et al, JNCI, 2013). Here we report the pathology, treatment and outcome of patients with TN tumours as a preliminary analysis to determine the impact of a germline BRCA1 mutation on survival. The whole cohort analysis including BRCA1 and BRCA2 is in progress.

Methods

2956 patients aged ≤40 at breast cancer diagnosis were recruited from 127 UK oncology centres between 2000 and 2008. Patient characteristics, family history, risk factors, tumour pathology and treatment information, and blood DNA were collected at recruitment. Follow-up data were collected at 6 and 12 months, then annually. Summary statistics were used to describe patients by BRCA1 status. Kaplan-Meier estimates were used to describe univariate survival data.

Results

BRCA1 status is currently available for 542 patients with TN tumours. Pathogenic BRCA1 mutations were identified in 122 patients (BRCA1+); 420 had no BRCA1 mutation (BRCA1-). BRCA1+ were younger than BRCA1- (median age 34 vs 36 years, p<0.001) and more likely to have a positive family history (p<0.001). There were no significant differences between BRCA1+ vs BRCA1- for: median tumour size (20.8mm vs 23.0mm); tumour grade distribution (95.8% grade 3 vs 93.6%); nodal involvement (35.2% node positive vs 39.9%); or presence of metastases at diagnosis (0.0% vs 1.0%).

Median follow-up was 7.3 years. Overall survival of patients with stage 1-3 disease treated with anthracycline +/- taxane neoadjuvant chemotherapy (n=538; 151 deaths) was better for BRCA1+ vs BRCA1- (79.1% vs 73.6% at 5-yrs; HR[95%CI]=0.84[0.57,1.25],p=0.388). Distant disease-free survival (DDFS) was also higher for BRCA1+ (5-yr DDFS 76.1% vs 71.5%; HR[CI]=0.92[0.63,1.35], p=0.682). Moreover, survival after first distant relapse was better for BRCA1+ patients (41.9% vs 36.8% at 1-yr; HR[CI]=0.78[0.51,1.18], p=0.233).

Conclusions

Our prospective data show better survival in young BRCA1+ patients with early TN breast cancer treated with anthracycline/-taxane chemotherapy than BRCA1- patients. However, the difference between the groups was not significant in this partial sample. Results for the whole cohort will be available by the time of the meeting.

Citation Format: Eccles DM, Copson ER, Maishman T, Tapper W, Cutress R, Gerty S, Stanton L, Altman DG, Durcan L, Simmonds P, Decker B, Allen J, Luccarini C, Easton D, Dunning A, POSH Steering Group and Collaborators. Does BRCA status affect outcome in young breast cancer patients? Results from the prospective study of outcomes in sporadic and hereditary breast cancer (POSH) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr S2-03.

Abstract PD6-02: Local recurrence in young women with invasive breast cancer; the prospective study of outcomes in sporadic and hereditary breast cancer (POSH)

Aim

To evaluate the surgical and clinical factors affecting local recurrence and other outcomes in young breast cancer patients using the POSH study.

Background

POSH (MREC:00/06/69) is a prospective cohort study of 3024 women aged 18-40 with breast cancer. Randomized controlled trials suggest equivalent survival between mastectomy and breast conserving surgery (BCS); however, very few young patients were included in these analyses. Emerging data also suggests a possible survival advantage for mastectomy in gene mutation carriers, and young age may be a predictor of higher rates of local recurrence.

Methods

Summary statistics were used to describe the cohort by surgical type (mastectomy or BCS). Study endpoints were in-breast ipsilateral local-recurrence interval, distant disease-free interval and overall survival. Cumulative hazard and Kaplan-Meier plots were used to describe survival data. Univariable and multivariable analyses were carried out using Cox proportional hazards models and flexible parametric survival (FPS) models (for any models with time-varying covariates).

Results

Of 2882 patients analysed, 1464 underwent mastectomy, 1395 BCS; and 23 had lymph node surgery only. Patients undergoing mastectomy had significantly larger tumours and higher proportions of positive Family History, positive estrogen receptor (ER+), progesterone receptor (PR+) and/or human epidermal growth factor 2 (HER2+) tumours. Local events only accounted for 15% of recurrences. Local recurrence varied over time by surgical type; local recurrence rate was similar at 18 months but higher for BCS compared to mastectomy at 5- and 10-years (18-months: 1.0% vs 1.0%, FPS-HR[95%CI]=1.43[0.89,2.32], p=0.348; 5-years: 5.3% vs 2.6%, FPS-HR[CI]=3.39[2.03,5.66], p<0.001; and 10-years: 11.7% vs 4.9%, FPS-HR[CI]=5.27[2.43,11.43], p<0.001, respectively). Similar results were found in the adjusted model and when restricting the analyses to patients with smaller tumours. Conversely, distant-metastases and death events were significantly lower for BCS but not after adjusting for prognostic factors. Chest-wall radiotherapy following mastectomy was associated with improved local recurrence interval (HR[CI]=0.46[0.24,0.86],p=0.015). Positive surgical margins, and the development of a local event, predicted for reduced distant disease free interval (HR[CI]=0.50[0.35,0.71],p<0.001; and 10-year FPS-HR[CI]=0.29[0.14,0.62],p=0.001, respectively).

Conclusions

In the short term, there is no difference in local recurrence between BCS and mastectomy in young women. Longer term, local recurrence is higher in BCS, but there is no difference in survival between surgical groups after adjusting for known prognostic factors. Surgical extent appears to be less important for distant relapse or death from breast cancer than completeness of excision or, where appropriate, chest-wall radiotherapy.

Acknowledgements

Data collection/analysis funded by CRUK (grants:A7572,A11699,C1275/A15956). Sponsored by UHS NHS Foundation Trust.

Citation Format: Maishman T, Cutress RI, Hernandez A, Gerty S, Copson ER, Durcan L, Eccles DM. Local recurrence in young women with invasive breast cancer; the prospective study of outcomes in sporadic and hereditary breast cancer (POSH) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD6-02.

Immunomodulators in SLE: Clinical evidence and immunologic actions

Systemic lupus erythematosus (SLE) is a potentially fatal autoimmune disease. Current treatment strategies rely heavily on corticosteroids, which are in turn responsible for a significant burden of morbidity, and immunosuppressives which are limited by suboptimal efficacy, increased infections and malignancies. There are significant deficiencies in our immunosuppressive armamentarium, making immunomodulatory therapies crucial, offering the opportunity to prevent disease flare and the subsequent accrual of damage. Currently available immunomodulators include prasterone (synthetic dehydroeipandrosterone), vitamin D, hydroxychloroquine and belimumab. These therapies, acting via numerous cellular and cytokine pathways, have been shown to modify the aberrant immune responses associated with SLE without overt immunosuppression. Vitamin D is important in SLE and supplementation appears to have a positive impact on disease activity particularly proteinuria. Belimumab has specific immunomodulatory properties and is an effective therapy in those with specific serological and clinical characteristics predictive of response. Hydroxychloroquine is a crucial background medication in SLE with actions in many molecular pathways. It has disease specific effects in reducing flare, treating cutaneous disease and inflammatory arthralgias in addition to other effects such as reduced thrombosis, increased longevity, improved lipids, better glycemic control and blood pressure. Dehydroeipandrosterone is also an immunomodulator in SLE which can have positive effects on disease activity and has bone protective properties. This review outlines the immunologic actions of these drugs and the clinical evidence supporting their use.

Family history and outcome of young patients with breast cancer in the UK (POSH study)

BACKGROUND

Young patients presenting to surgical clinics with breast cancer are usually aware of their family history and frequently believe that a positive family history may adversely affect their prognosis. Tumour pathology and outcomes were compared in young British patients with breast cancer with and without a family history of breast cancer.

METHODS

Prospective Outcomes in Sporadic versus Hereditary breast cancer (POSH) is a large prospective cohort study of women aged less than 41 years with breast cancer diagnosed and treated in the UK using modern oncological management. Personal characteristics, tumour pathology, treatment and family history of breast/ovarian cancer were recorded. Follow-up data were collected annually.

RESULTS

Family history data were available for 2850 patients. No family history was reported by 65·9 per cent, and 34·1 per cent reported breast/ovarian cancer in at least one first- or second-degree relative. Patients with a family history were more likely to have grade 3 tumours (63·3 versus 58·9 per cent) and less likely to have human epidermal growth factor receptor 2-positive tumours (24·7 versus 28·8 per cent) than those with no family history. In multivariable analyses, there were no significant differences in distant disease-free intervals for patients with versus those without a family history, either for the whole cohort (hazard ratio (HR) 0·89, 95 per cent c.i. 0·76 to 1·03; P = 0·120) or when stratified by oestrogen receptor (ER) status (ER-negative: HR 0·80, 0·62 to 1·04, P = 0·101; ER-positive: HR 0·95, 0·78 to 1·15, P = 0·589).

CONCLUSION

Young British patients presenting to breast surgical clinics with a positive family history can be reassured that this is not a significant independent risk factor for breast cancer outcome.

An evaluation of the prognostic model PREDICT using the POSH cohort of women aged ⩽40 years at breast cancer diagnosis

BACKGROUND

Breast cancer is the most common cancer in younger women (aged ⩽40 years) in the United Kingdom. PREDICT (http://www.predict.nhs.uk) is an online prognostic tool developed to help determine the best available treatment and outcome for early breast cancer. This study was conducted to establish how well PREDICT performs in estimating survival in a large cohort of younger women recruited to the UK POSH study.

METHODS

The POSH cohort includes data from 3000 women aged ⩽40 years at breast cancer diagnosis. Study end points were overall and breast cancer-specific survival at 5, 8, and 10 years. Evaluation of PREDICT included model discrimination and comparison of the number of predicted versus observed events.

RESULTS

PREDICT provided accurate long-term (8- and 10-year) survival estimates for younger women. Five-year estimates were less accurate, with the tool overestimating survival by 25% overall, and by 56% for patients with oestrogen receptor (ER)-positive tumours. PREDICT underestimated survival at 5 years among patients with ER-negative tumours.

CONCLUSIONS

PREDICT is a useful tool for providing reliable long-term (10-year) survival estimates for younger patients. However, for more accurate short-term estimates, the model requires further calibration using more data from young onset cases. Short-term prediction may be most relevant for the increasing number of women considering risk-reducing bilateral mastectomy.

Obesity and the outcome of young breast cancer patients in the UK: the POSH study

BACKGROUND

Obese breast cancer patients have a poorer prognosis than non-obese patients. We examined data from a large prospective cohort study to explore the associations of obesity with tumour pathology, treatment and outcome in young British breast cancer patients receiving modern oncological treatments.

PATIENTS AND METHODS

A total of 2956 patients aged ≤40 at breast cancer diagnosis were recruited from 126 UK hospitals from 2001 to 2007. Height and weight were measured at registration. Tumour pathology and treatment details were collected. Follow-up data were collected at 6, 12 months, and annually.

RESULTS

A total of 2843 eligible patients (96.2%) had a body mass index (BMI) recorded: 1526 (53.7%) were under/healthy-weight (U/H, BMI <25 kg/m(2)), 784 (27.6%) were overweight (ov, BMI ≥25 to <30), and 533 (18.7%) were obese (ob, BMI ≥30). The median tumour size was significantly higher in obese and overweight patients than U/H patients (Ob 26 mm versus U/H 20 mm, P < 0.001; Ov 24 mm versus U/H 20 mm, P < 0.001). Obese and overweight patients had significantly more grade 3 tumours (63.9% versus 59.0%, P = 0.048; Ov 63.6% versus U/H 59.0% P = 0.034) and node-positive tumours (Ob 54.6% versus U/H 49.0%, P = 0.027; Ov 54.2% versus U/H 49%, P = 0.019) than U/H patients. Obese patients had more ER/PR/HER2-negative tumours than healthy-weight patients (25.0% versus 18.3%, P = 0.001). Eight-year overall survival (OS) and distant disease-free interval (DDFI) were significantly lower in obese patients than healthy-weight patients [OS: hazard ratio (HR) 1.65, P < 0.001; DDFI: HR 1.44, P < 0.001]. Multivariable analyses adjusting for tumour grade, size, nodal, and HER2 status indicated that obesity was a significant independent predictor of OS and DDFI in patients with ER-positive disease.

CONCLUSIONS

Young obese breast cancer patients present with adverse tumour characteristics. Despite adjustment for this, obesity still independently predicts DDFI and OS.

Ethnicity and outcome of young breast cancer patients in the United Kingdom: the POSH study

BACKGROUND

Black ethnic groups have a higher breast cancer mortality than Whites. American studies have identified variations in tumour biology and unequal health-care access as causative factors. We compared tumour pathology, treatment and outcomes in three ethnic groups in young breast cancer patients treated in the United Kingdom.

METHODS

Women aged ≤ 40 years at breast cancer diagnosis were recruited to the POSH national cohort study (MREC: 00/06/69). Personal characteristics, tumour pathology and treatment data were collected at diagnosis. Follow-up data were collected annually. Overall survival (OS) and distant relapse-free survival (DRFS) were assessed using Kaplan-Meier curves, and multivariate analyses were performed using Cox regression.

RESULTS

Ethnicity data were available for 2915 patients including 2690 (91.0%) Whites, 118 (4.0%) Blacks and 87 (2.9%) Asians. Median tumour diameter at presentation was greater in Blacks than Whites (26.0 mm vs 22.0 mm, P=0.0103), and multifocal tumours were more frequent in both Blacks (43.4%) and Asians (37.0%) than Whites (28.9%). ER/PR/HER2-negative tumours were significantly more frequent in Blacks (26.1%) than Whites (18.6%, P=0.043). Use of chemotherapy was similarly high in all ethnic groups (89% B vs 88.6% W vs 89.7% A). A 5-year DRFS was significantly lower in Blacks than Asians (62.8% B vs 77.0% A, P=0.0473) or Whites (62.8 B% vs 77.0% W, P=0.0053) and a 5-year OS for Black patients, 71.1% (95% CI: 61.0-79.1%), was significantly lower than that of Whites (82.4%, 95% CI: 80.8-83.9%, W vs B: P=0.0160). In multivariate analysis, Black ethnicity had an effect on DRFS in oestrogen receptor (ER)-positive patients that is independent of body mass index, tumour size, grade or nodal status, HR: 1.60 (95% CI: 1.03-2.47, P=0.035).

CONCLUSION

Despite equal access to health care, young Black women in the United Kingdom have a significantly poorer outcome than White patients. Black ethnicity is an independent risk factor for reduced DRFS particularly in ER-positive patients.

Fracture liaison service in a non-regional orthopaedic clinic--a cost-effective service

Fracture liaison services (FLS) aim to provide cost-effective targeting of secondary fracture prevention. It is proposed that a dedicated FLS be available in any hospital to which a patient presents with a fracture. An existing orthopaedic clinic nurse was retrained to deliver a FLS. Proformas were used so that different nurses could assume the fracture liaison nurse (FLN) role, as required. Screening consisted of fracture risk estimation, phlebotomy and DXA scanning. 124 (11%) of all patients attending the orthopaedic fracture clinic were reviewed in the FLS. Upper limb fractures accounted for the majority of fragility fractures screened n=69 (55.6%). Two-thirds of patients (n=69) had reduced bone mineral density (BMD). An evidence based approach to both non-pharmacological and pharmacotherapy was used and most patients (76.6%) receiving pharmacotherapy received an oral bisphosphonate (n=46). The FLS has proven to be an effective way of delivering secondary prevention for osteoporotic fracture in a non-regional fracture clinic, without increasing staff costs.

P2-12-03: A Prospective Study of the Prognostic Implications of Being a BRCA1 Carrier for Young Onset Breast Cancer Patients

Background

BRCA1 gene carriers frequently develop triple negative breast cancer (TNBC) at young ages. Retrospective studies have reached conflicting conclusions about the prognostic implications of breast cancer diagnosed on a background of a constitutional BRCA1 gene mutation. Many studies have the disadvantages of retrospective design and small numbers or both. The Prospective study of Outcomes in Sporadic versus Hereditary breast cancer (POSH) recruited 3024 patients diagnosed before 41 years of age and treated for breast cancer in the UK between 2000 and 2007 (protocol published: Eccles et al BMC Cancer 2008).

Aim: To investigate the effect of family history and BRCA1 gene mutation status on breast cancer survival in women aged younger than 41 years at diagnosis.

Methods: Cases in which the primary tumour pathology report was not available (2.8% of total) were excluded from this analysis. A completed family history questionnaire was available for 2907 cases (99% of total). The primary end point for this analysis was the development of distant metastases from breast cancer. All patients were younger than the starting age for screening in the UK except for known gene carriers of which there were only 8 in total, the remainder of identified gene carriers were tested after cancer diagnosis or as part of this study. Over 90% of patients received adjuvant or neoadjuvant chemotherapy with over 90% of these receiving an anthracycline based regimen. Kaplan Meier survival analysis and log rank test were used to assess survival differences.

Results: 2937 patients were included in the analysis. Mean and median age at diagnosis was 36 years and the cohort was followed prospectively for a mean and median follow up time of 50 months. Overall distant disease free survival in the whole cohort was only 75% at 5 years. The effect of family history on presentation was explored. Patients who reported a first or second degree relative with breast cancer presented with smaller tumours (20mm compared to 22.5mm, p= 0.006) but no difference in axillary nodal status (p=0.2605). Survival was however significantly better comparing the 499 patients who reported a family history of breast cancer compared with the rest of the cohort (p=0.0164). 539 patients had been tested for mutations in the BRCA1/2 genes and 176 high risk gene BRCA1/BRCA2 carriers were identified. We compared 118 patients with a known BRCA1 gene mutation (almost all diagnosed after the cancer) to the 465 patients with confirmed TNBC (p=0.0118). Survival was significantly better in the BRCA1 carriers (p=0.0118). After excluding 29 gene carriers whose primary tumour showed any of ER, HER2 or PR as positive, the same improved survival trend was seen although significant at the 10% level (p=0.07).

Conclusion: This prospective study indicates that BRCA1 gene carriers clearly do not have a worse prognosis when compared to triple negative breast cancers or young onset breast cancer overall and these early follow up data indicate an improved outlook in gene carriers.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-12-03.

A Novel Tumour-Based Test To Identify Breast Cancer Due to BRCA1 and BRCA2 Mutations

Background: Family history and young onset are the usual indicators of an underlying genetic predisposition to breast cancer development. BRCA1 associated breast tumours are more likely to be ER negative and express “basal” markers, however most patients with ER negative/ basal marker positive breast cancers (especially young onset) do not have inherited BRCA1 mutations. BRCA1 and BRCA2 gene carriers may have novel treatment options available and may need to consider future cancer prevention strategies. Genetic counselling and germline mutation analysis remains a relatively expensive option that is not appropriate for most breast cancer patients.Aim: To design a sensitive and specific pathology based predictor that would improve identification of BRCA1 and 2 gene carriers.Method: We assembled a training panel of breast cancer tumour blocks from 67 BRCA1, 71 BRCA2 associated and 105 sporadic young onset cases (≤ 40 years at diagnosis). All gene carriers were diagnosed before 50 years and were matched to sporadic cases for ER status. Tissue micro arrays (TMAs) were assembled and subjected to immunohistochemical analysis with a panel of 18 antibodies. DNA was extracted from micro dissected tumour tissue and matched patient lymphocytes and subjected to high resolution tiling path microarray-based Comparative Genomic Hybridisation (aCGH). Using robust statistical approaches, regions significantly differentially lost, gained or amplified in BRCA1, BRCA2 and controls were identified. Probes for chromogenic in situ hybridisation (CISH) for amplified regions were generated.Results: Two differentially amplified clones in BRCA1 cases designated P1 at 3q25.31 and P2 at 3q25.2 and one in BRCA2 cases, P3 at 20q13.13, were identified and amplifications validated in the training set using CISH. Logistic regression analysis of the panel comprising CISH and IHC markers was used to develop the best predictor. The best predictor for BRCA1 gene carriers was a combination of P1, ER and HER2. This combination outperformed all combinations of immunohistochemical markers, including ER and basal markers; the Positive Predictive Value (PPV) was 87.5% and NPV 92% giving a Receiver Operator Characteristic (ROC) curve with an AUC of 0.92 (CI 0.88-0.97). The BRCA2 signature panel is currently being evaluated. These BRCA1 and BRCA2 predictor panels are being validated in a new set of TMAs comprising 223 tumours from the POSH study1.Conclusion: This tumour based predictor for BRCA1 and BRCA2 carriers may prove useful to identify gene carriers at low a priori chance of having a mutation, to direct BRCA1/2 targeted treatment approaches and to identify familial non BRCA1/2 cases that may be suitable for new gene discovery studies.1. Eccles D et al. BMC Cancer 2007; 7(1):160.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5032.

Chronic inflammatory demyelinating polyneuropathy (CIDP) in diabetics

Seven diabetic patients developed a progressive, moderately severe, motor rather than sensory neuropathy predominantly affecting the legs. This met clinical and electrophysiological criteria for chronic inflammatory demyelinating polyneuropathy (CIDP). Nerve biopsies showed a variety of abnormalities, none of which clearly distinguished between diabetic polyneuropathy and CIDP. The patients were treated with combinations of corticosteroids, azathioprine, plasmapheresis and intravenous immune globulin; all improved substantially. We believe that CIDP may masquerade as unusually severe and progressive diabetic distal symmetric polyneuropathy. It is important to recognize CIDP in diabetics because, unlike diabetic polyneuropathy, CIDP is treatable.