Pulmonary neuroendocrine tumours and somatostatin receptor status: an assessment of unlicensed use of somatostatin analogues in the clinical practice

Background

The use of somatostatin analogues (SSAs) has not been formally approved in pulmonary neuroendocrine tumours (NETs) in the absence of positive controlled trials, even though it is recommended as a potential therapeutic option in recent guidelines.

Patients and methods

We have assessed the use of SSA in the general practice in Austria by retrospectively analysing patients with pulmonary NETs referred to our European Neuroendocrine Tumor Society centre in Vienna for second opinion or further therapy. In addition, we have analysed the somatostatin receptor (SSTR) expression of those patients by immunohistochemistry (IHC) and SSTR imaging, e.g. ⁶⁸Ga-DOTANOC-positron emission tomography/computed tomography, and whether such analyses had been carried out before referral at our centre.

Results

Out of 34 patients (19 atypical and 15 typical carcinoids) with metastatic or advanced disease, 10/34 (29%) had been prescribed SSA before referral. No IHC for SSTR had been carried out, and only 9/34 (27%) had undergone SSTR imaging by nuclear medicine. Sufficient material for IHC was available in 29/34 (85%) patients and SSTR-IHC was rated negative in 13/29 (45%), weakly positive in 4/29 (14%), moderately positive in 5/29 (17%) and strongly positive in 7/29 (24%) patients. On SSTR imaging, 8/34 patients (24%) were positive, 13/34 (38%) negative and 13/34 patients (38%) showed a mix of positive and negative NET lesions. In 11/29 (38%) patients with both IHC and imaging available, discordance of SSTR expression on imaging and histological assessment was detected.

Conclusions

These data show that uncritical use of SSA should be discouraged, and assessment of SSTR, preferably by imaging, is mandatory before prescription of SSA in pulmonary NETs.

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SSAs are not formally approved in pulmonary NETs.

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SSAs are recommended as a potential therapeutic option for advanced lung NETs in guidelines.

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We assessed the use of SSAs for lung NET in the general practice in Austria.

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Only 27% had undergone SSTR imaging before referral and receptor status was highly heterogeneous.

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Our data emphasize that uncritical use of SSAs should be discouraged; assessment of SSTRs is recommended.

Supervised machine learning enables non-invasive lesion characterization in primary prostate cancer with [68Ga]Ga-PSMA-11 PET/MRI

PURPOSE

Risk classification of primary prostate cancer in clinical routine is mainly based on prostate-specific antigen (PSA) levels, Gleason scores from biopsy samples, and tumor-nodes-metastasis (TNM) staging. This study aimed to investigate the diagnostic performance of positron emission tomography/magnetic resonance imaging (PET/MRI) in vivo models for predicting low-vs-high lesion risk (LH) as well as biochemical recurrence (BCR) and overall patient risk (OPR) with machine learning.

METHODS

Fifty-two patients who underwent multi-parametric dual-tracer [18F]FMC and [68Ga]Ga-PSMA-11 PET/MRI as well as radical prostatectomy between 2014 and 2015 were included as part of a single-center pilot to a randomized prospective trial (NCT02659527). Radiomics in combination with ensemble machine learning was applied including the [68Ga]Ga-PSMA-11 PET, the apparent diffusion coefficient, and the transverse relaxation time-weighted MRI scans of each patient to establish a low-vs-high risk lesion prediction model (MLH). Furthermore, MBCR and MOPR predictive model schemes were built by combining MLH, PSA, and clinical stage values of patients. Performance evaluation of the established models was performed with 1000-fold Monte Carlo (MC) cross-validation. Results were additionally compared to conventional [68Ga]Ga-PSMA-11 standardized uptake value (SUV) analyses.

RESULTS

The area under the receiver operator characteristic curve (AUC) of the MLH model (0.86) was higher than the AUC of the [68Ga]Ga-PSMA-11 SUVmax analysis (0.80). MC cross-validation revealed 89% and 91% accuracies with 0.90 and 0.94 AUCs for the MBCR and MOPR models respectively, while standard routine analysis based on PSA, biopsy Gleason score, and TNM staging resulted in 69% and 70% accuracies to predict BCR and OPR respectively.

CONCLUSION

Our results demonstrate the potential to enhance risk classification in primary prostate cancer patients built on PET/MRI radiomics and machine learning without biopsy sampling.

P16INK4A immunohistochemistry for detection of human papilloma virus-associated penile squamous cell carcinoma is superior to in-situ hybridization

We evaluated p16INK4A as a reliable option to detect human papilloma virus (HPV) DNA in penile tumor specimens. Formalin-fixed paraffin embedded samples of 26 patients with penile cancer and another 18 cases with non-tumorigenic lesions were stained by three different widely used commercially available chromogenic in-situ hybridization assays high-risk HPV CISH Y1443 (Genpoint, DAKO), pan HPV CISH Y1404 (Genpoint, DAKO), INFORM HPV III (Ventana, Tucson, Arizona) and p16INK4A immunohistochemistry, then compared to the known gold standard polymerase chain reaction detecting HPV 16, 18, 31, and 33. Immunoreactivity for p16INK4A was evaluated by using a 4-tiered (0, 1, 2, and 3) pattern based system. 19 cases were positive for p16INK4A, 13 of which showed a continuous transepithelial staining (pattern 3). Pan HPV ISH showed positivity in 9 cases, high-risk HPV ISH in 7 cases and INFORM HPVIII ISH in 7 cases. p16INK4A IHC pattern 3 versus pattern 0, 1 and 2 exhibited a specificity and positive predictive value of 100 percent, with a sensitivity and negative predictive value of 72 and 62 percent, respectively, which was much better than all HPV in-situ hybridization methods referred to polymerase chain reaction. p16INK4A seems to be a superior marker for the detection of HPV-associated penile squamous cell carcinoma compared to CISH tests, but is not recommend for the detection of non-tumorigenic lesions, where PCR should be used for the initial assessment.

Pathological features of prostate cancer detected on initial and repeat prostate biopsy: results of the prospective European Prostate Cancer Detection study

PURPOSE

We evaluated pathological features of prostate cancer detected on repeat prostate biopsy in men with a serum total prostate-specific antigen (PSA) level between 4 and 10 ng/ml who were diagnosed with benign prostatic tissue after an initial biopsy and compared them to those cancers detected on initial prostate biopsy.

MATERIALS AND METHODS

In this prospective European prostate cancer detection study, 1,051 men with a total PSA level between 4 and 10 ng/ml underwent transrectal ultrasound (TRUS)-guided sextant biopsy and two additional transition zone biopsies. All subjects whose biopsy samples were negative for prostate cancer (CaP) underwent a repeat biopsy after 6 weeks. Those with clinically localized cancers underwent radical prostatectomy. Pathological and clinical features of patients diagnosed with cancer on either initial or repeat biopsy and clinically organ confined disease who agreed to undergo radical prostatectomy were compared.

RESULTS

Initial biopsy was positive (CaP) in 231 of 1,051 enrolled subjects and negative (benign histology) in 820 subjects. Of these 820 subjects, CaP was detected in 10% (83/820) upon repeat biopsy. Of cancers detected on initial and repeat biopsy, 148/231 (64%) and 56/83 (67.5%) had clinically localized disease, respectively, and were offered radical prostatectomy. 10/148 (6.7%) and 3/56 (5.3%), respectively, opted for radiation therapy and thus, 138/148 (93.3%) and 53/56 (94.7%), respectively, underwent radical retropubic prostatectomy. There were statistically significant differences with respect to multifocality (P = 0.009) and cancer location (P < 0.001) with cancers on repeat biopsy showing a lower rate of multifocality and a more apico-dorsal location. In contrast, there were no differences with respect to stage (P = 0.2), Gleason score (P = 0.36), percentage Gleason grade 4/5 (P = 0.1), serum PSA (P = 0.62), and patient age (P = 0.517).

CONCLUSIONS

At least 10% of patients with negative prostatic biopsy results will be diagnosed with CaP on repeat biopsy. Despite differences in location and multifocality, pathological and biochemical features of cancers detected on initial and repeat biopsy are similar, suggesting similar biological behavior and thus advocating for a repeat prostate biopsy in case of a negative finding on initial biopsy. Cancers missed on initial biopsy and subsequently detected on repeat biopsy are located in a more apico-dorsal location. Repeat biopsies should thus be directed to this rather spared area in order to improve cancer detection rates.

Preoperative embolization of intracranial meningiomas: a 17-years single center experience

The purpose of the present report is to review the evolution of endovascular therapy at our center as utilized for the preoperative embolization of intracranial meningiomas over a 17-years period (1982-1998). This study is based upon a consecutive series of 63 patients who underwent preoperative embolization of intracranial meningiomas. Total or subtotal angiographic devascularization of the tumor parenchyma was accomplished in 38 patients (60.3%) who had tumors with either an external carotid artery supply only (n = 30) or with contributions from the cavernous carotid artery, ophthalmic artery, vertebral artery, or pial feeders which were feasible for selective embolization (n = 8). Partial tumor embolizations were attained in the remaining 25 patients (39.7%) because 1. the remanent feeders were considered easily accessible to surgical control in the early stages of dissection, 2. the feeding branches were inaccessible for a microcatheter approach, or 3. superselective microcatheter positions allowing for safe embolization without reflux of embolic material into physiological branches were not achieved. Overall, 97 of 126 tumor feeders identified angiographically were catheterized to selective embolization (77%). Three embolization related complications occurred early in our experience (1982-1989) using techniques which no longer meet standards of treatment. In light of the remarkable evolution of endovascular techniques over the 17-years study period, however, we conclude that preoperative embolization of intracranial meningiomas can be performed safely with the endovascular tools currently available.

Development of HIV encephalitis in AIDS and TNF-alpha regulatory elements

Tumor necrosis factor-alpha (TNF-alpha) appears to play an important role in HIV encephalitis (HIVE). TNF2, a polymorphism of TNF-alpha, associates with higher levels of TNF-alpha and severe manifestations of some infections. We studied 44 acquired immunodeficiency syndrome (AIDS) patients with autopsy-proven HIVE and/or HIV leukoencephalopathy (HIVLE) (HIVE/LE) and 30 AIDS patients without HIVE/LE. TNF2 did not associate with presence of HIVE/LE (p > 0.5). Moreover, the TNF-alpha regulatory element TTATTTAT within the 3'-untranslated region was intact in HIVE/LE brains, and HLA-DR3 did not associate with HIVE/LE. Other host factors or, more likely, viral factors may be responsible for the development of HIVE/LE.

Expression of regulatory apoptotic proteins in peripheral giant cell granulomas and lesions containing osteoclast-like giant cells

Peripheral giant cell granuloma consists of mononuclear cells and osteoclast-like giant cells. The proliferative ability of peripheral giant cell granuloma is restricted to the mononuclear cell compartment, whereas multinucleated giant cells lack mitotic activity. Although the proliferative compartment of peripheral giant cell granuloma has been investigated in detail, the expression and distribution of proteins regulating apoptosis is unknown. The present study demonstrates strong expression of bak and bax in the majority of giant cells. In contrast, giant cells show only weak positivity for bcl-2 and moderate positivity for bcl-x. Mononuclear cells were negative to weakly positive for bcl-x. Only scattered mononuclear cells were positive for bak, bax and bcl-2. The frequency of apoptotic nuclei detected by TUNEL-staining compared to regular nuclei was 18 times higher in giant cells than in mononuclear cells. In summary, our findings support the presumption that giant cells of bone and soft tissue tumors are reactive cell forms and not of neoplastic origin.