Comparative study of the PD-L1 status between surgically resected specimens and matched biopsies of NSCLC patients reveal major discordances: a potential issue for anti-PD-L1 therapeutic strategies.

BACKGROUND: High expression of programmed death ligand-1 (PD-L1) on tumor cells (TC) and/or on tumor-infiltrating immune cells (IC) is associated with a high response rate in patients with advanced nonsmall-cell lung cancer (NSCLC) treated with PD-L1 inhibitors. The use of a PD-L1 immunohistochemical (IHC) test in determining the responsiveness to immunotherapy has raised the question of the reliability and reproducibility of its evaluation in lung biopsies compared with corresponding resected surgical specimens. PATIENTS AND METHODS: PD-L1 expression in TC and IC was assessed in 160 patients with operable NSCLC on both whole surgical tissue sections and matched lung biopsies, by using a highly sensitive SP142 IHC assay. The specimens were scored as TC 0-3 and IC 0-3 based on increasing PD-L1 expression. RESULTS: PD-L1 expression was frequently discordant between surgical resected and matched biopsy specimens (the overall discordance rate = 48%; 95% confidence interval 4.64-13.24) and κ value was equal to 0.218 (poor agreement). In all cases, the biopsy specimens underestimated the PD-L1 status observed on the whole tissue sample. PD-L1-positive IC tumors were more common than PD-L1-positive TC tumors on resected specimens. The discrepancies were mainly related to the lack of a PD-L1-positive IC component in matched biopsies. CONCLUSIONS: Our results indicate relatively poor association of the PD-L1 expression in TC and IC between lung biopsies and corresponding resected tumors. Although these results need to be further validated in larger cohorts, they indicate that the daily routine evaluation of the PD-L1 expression in diagnostic biopsies can be misleading in defining the sensitivity to treatment with PD-L1 targeted therapy.

[Prognostic value of toxicities induced by targeted therapies in patients treated for a metastatic renal cell carcinoma]. / Valeur pronostique de la toxicité induite par les thérapies ciblées dans le carcinome rénal métastatique.

OBJECTIVE: To assess the prognostic value of clinical and biological variables in the era of targeted therapies, especially induced toxicity in patients treated for metastatic renal cell carcinoma (RCC). PATIENTS AND METHODS: A retrospective single-center study was performed in patients treated in our center from 2006 to 2012. The clinical and biological variables and toxicity data were retrospectively collected. Survival rates were calculated using the Kaplan-Meier method and compared by the Log-Rank test. Multivariate analysis was also performed using the Cox model. RESULTS: One hundred and two patients were included, with a median follow-up of 20 months. The median overall survival (OS) was 21 months, and 6 months for the progression free survival (PFS). As expected, the variables included in the Mozter prognostic score had a significant impact on OS (P < 0.0001) and PFS (P < 0.0001). However, hypoalbuminemia (P < 0.0001), brain metastasis (P = 0.003) and the absence of nephrectomy (P < 0.0001) were found as poor prognosis factors for OS. In addition, severe toxicity (grade 3-4) was significantly associated with higher OS (P < 0.0001) and PFS (P = 0.0003) and appeared as an independent factor in multivariate analysis for OS (P = 0.02) and PFS (P = 0.01). CONCLUSION: Severe toxicity induced by targeted therapies was found as a prognostic factor increasing significantly the survival. Further studies are needed to assess the real value of this factor in the development of sequential therapies for the treatment of RCC.

The colorectal cancer stem-like cell hypothesis: a pathologist's point of view.

Colorectal cancer is the fourth most common cancer in men and the third most common cancer in women worldwide. The partial failure of classic therapeutic options makes scientists to doubt the efficacy of systemic treatments in targeting the essential cell populations and achieving cure as a final goal. Overgrowing data suggest that cancer is a disease closely linked to stem cells (SCs). It is well known that the first identification of cancer stem-like cells in acute myeloid leukaemia was soon followed by similar results in solid malignancies, including colorectal cancer, and the classic model for colon carcinogenesis supports the development of sudden mutations that will lead to the activation or inactivation of certain oncogenes or tumor suppressors. Thus, this process may go on for years before the first symptoms and the only cells able to withstand for many years, avoid apoptosis and have a high regenerative capacity are the progenitor cells found at the lower part of colon crypts. A more profound study of the mechanisms and molecular signalling pathways that control the basic characteristics of SCs, such as asymmetrical division or self-renewal, may help comprehend the basic mechanisms of cancer genesis and progression. This will result in the development of new therapeutic agents that may target chemoresistant cell populations and improve the therapeutic results. In the current review we point out the importance of cancer stem-like cells in colorectal oncology from a pathologist's point of view, stating the obvious correlation between histology, embryology and surgical pathology.

Molecular determinants of anti-EGFR sensitivity and resistance in metastatic colorectal cancer.

Since 2004, the clinical impact of monoclonal antibodies (mAbs) targeting the epidermal growth factor receptor (EGFR) on patients with metastatic colorectal cancer (MCRC) has been clearly established. The combination of these biological agents with conventional chemotherapy has led to a significant improvement in response rate, progression-free survival and overall survival in first-line as well as in second- or third-line treatment of MCRC. However, the high variability of response and outcome in MCRC patients treated with these anti-EGFR mAbs has highlighted the need of identifying clinical and/or molecular predictive markers to ensure appropriate use of targeted therapies. The presence of somatic KRAS mutations has been clearly identified as a predictive marker of resistance to anti-EGFR in MCRC, and the use of anti-EGFR mAbs is now restricted to patients with no detectable KRAS mutation. Several studies have indicated that amplification of EGFR, overexpression of the EGFR ligands and inactivation of the anti-oncogene TP53 are associated with sensitivity to anti-EGFR mAbs, whereas mutations of BRAF and PIK3CA and loss of PTEN expression are associated with resistance. Besides these somatic variations, germline polymorphisms such as those affecting genes involved in the EGFR pathway or within the immunoglobulin receptors may also modulate response to anti-EGFR mAbs. Until now, all these markers are not completely validated and only KRAS genotyping is mandatory in routine practice for use of the anti-EGFR mAbs in MCRC.

[Multiple ovarian fibromas in a patient with Gorlin syndrome: US and MR imaging features with pathological correlation]. / Fibromes ovariens multiples chez une patiente atteinte du syndrome de Gorlin.

We report a case of multiple ovarian fibromas in a 23 year old woman with Gorlin syndrome. We describe the US and MR imaging features with pathological correlation. The fibrous component of the tumors were hypoechoic and attenuating on US with corresponding T2W hypointensity whereas myxoid components were hypoechoic with increased through transmission on US with corresponding T2W hyperintensity.

TP53 mutations predict disease control in metastatic colorectal cancer treated with cetuximab-based chemotherapy.

Recent studies have suggested that activation of the EGFR pathway leads to malignant transformation only if the p53 protein is inactivated. Therefore, we evaluated the impact of TP53 mutations on cetuximab-based chemotherapy (CT) sensitivity in combination with KRAS mutations that have been associated with cetuximab resistance. KRAS and TP53 status were assessed in tumours from 64 metastatic colorectal cancer patients treated with cetuximab-based CT and correlated to clinical response using the Fisher's exact test. Times to progression (TTPs) according to gene status were calculated using the Kaplan-Meier method and compared with log-rank test. TP53 mutations were found in 41 patients and were significantly associated with controlled disease (CD), as defined as complete response, partial response or stable disease (P=0.037) and higher TTP (20 vs 12 weeks, P=0.004). Remarkably, in the subgroup of 46 patients without KRAS mutation, but not in patients with KRAS mutation, TP53 mutations were also associated with CD (P=0.008) and higher TTP (24 vs 12 weeks, P=0.0007). This study suggests that TP53 mutations are predictive of cetuximab sensitivity, particularly in patients without KRAS mutation, and that TP53 genotyping could have a clinical interest to select patients who should benefit from cetuximab-based CT.

Frequent alteration of DNA damage signalling and repair pathways in human colorectal cancers with microsatellite instability.

Accumulation of frameshift mutations at genes containing coding mononucleotide repeats is thought to be the major molecular mechanism by which mismatch repair-deficient cells accumulate functional alterations. These mutations resulting from microsatellite instability (MSI) can affect genes involved in pathways with a putative oncogenic role, but may also arise in genes without any expected role in MSI carcinogenesis because of the high mutation background of these tumours. We here screened 39 MSI colorectal tumours for the presence of mutations in 25 genes involved in DNA damage signalling and repair pathways. Using a maximum likelihood statistical method, these genes were divided into two different groups that differed significantly in their mutation frequencies, and likely represent mutations that do or do not provide selective pressure during MSI tumour progression. Interestingly, the so-called real-target mutational events were found to be distributed among genes involved in different functional pathways of the DNA metabolism, for example, DNA damage signalling (DNA-PKcs, ATR), double-strand break (DSB) repair (DNA-PKcs, RAD50), mismatch repair (MSH3, MSH6, MBD4) and replication (POLD3). In particular, mutations in MRE11 and/or RAD50 were observed in the vast majority of the tumours and resulted in the concomitant loss of immunohistochemical expression of both proteins. These data might explain why MSI colorectal cancers (CRC) behave differently in response to a wide variety of chemotherapeutic agents, notably those targeting DNA. More generally, they give further insights into how MSI leads to functional changes with synergistic effects in oncogenic pathways.

Adult human spinal cord harbors neural precursor cells that generate neurons and glial cells in vitro.

Adult human and rodent brains contain neural stem and progenitor cells, and the presence of neural stem cells in the adult rodent spinal cord has also been described. Here, using electron microscopy, expression of neural precursor cell markers, and cell culture, we investigated whether neural precursor cells are also present in adult human spinal cord. In well-preserved nonpathological post-mortem human adult spinal cord, nestin, Sox2, GFAP, CD15, Nkx6.1, and PSA-NCAM were found to be expressed heterogeneously by cells located around the central canal. Ultrastructural analysis revealed the existence of immature cells close to the ependymal cells, which display characteristics of type B and C cells found in the adult rodent brain subventricular region, which are considered to be stem and progenitor cells, respectively. Completely dissociated spinal cord cells reproducibly formed Sox2(+) nestin(+) neurospheres containing proliferative precursor cells. On differentiation, these generate glial cells and gamma-aminobutyric acid (GABA)-ergic neurons. These results provide the first evidence for the existence in the adult human spinal cord of neural precursors with the potential to differentiate into neurons and glia. They represent a major interest for endogenous regeneration of spinal cord after trauma and in degenerative diseases.

[Sentinel lymph node biopsy in gastro-intestinal surgery: facts and future implications]. / Le ganglion sentinelle en pathologie digestive: données actuelles et implications à venir.

In theory, the concept of sentinel lymph node (SLN) biopsy can be applied to cancer surgery for all solid cancers. Yet sentinel lymph node biopsy has not become a standard part of gastrointestinal cancer surgery. It has been of value in the assessment of small early-stage gastric cancers, but has only achieved widespread practice in Japan. Studies of SLN biopsy in colon cancer have not shown it to be a reliable predictor of N+ status and therefore don't permit the omission of lymph node dissection in selected cases. On the other hand, as a form of intra-operative lymph node mapping, dye injection of the SLN may demonstrate aberrant lymphatic drainage and could occasionally permit the sparing of a middle colic artery whose sacrifice would otherwise be dictated by standard drainage patterns. SLN biopsy may have prognostic usefulness by demonstrating micrometastases; careful serial sectioning focussed on the SLN may detect nests of metastatic cells on HE staining, thereby converting a tumor from Stage I (TxN0M0) to Stage II (TxN1M0). This finding has been noted in 10-15% of cases. However, the prognostic value of micrometastases detected only by immunohistochemical staining or PCR has not been demonstrated. For cancers of the anal canal, SLN biopsy of inguinal nodes has been tested as a means of establishing the indications for inguinal lymph node dissection.

[Not Available]. / Le ganglion sentinelle en pathologie digestive : données actuelles et implications à venir.

M. Pocard, J.-C. Sabourin In theory, the concept of sentinel lymph node (SLN) biopsy can be applied to cancer surgery for all solid cancers. Yet sentinel lymph node biopsy has not become a standard part of gastrointestinal cancer surgery. It has been of value in the assessment of small early-stage gastric cancers, but has only achieved widespread practice in Japan. Studies of SLN biopsy in colon cancer have not shown it to be a reliable predictor of N+ status and therefore don't permit the omission of lymph node dissection in selected cases. On the other hand, as a form of intra-operative lymph node mapping, dye injection of the SLN may demonstrate aberrant lymphatic drainage and could occasionally permit the sparing of a middle colic artery whose sacrifice would otherwise be dictated by standard drainage patterns. SLN biopsy may have prognostic usefulness by demonstrating micrometastases; careful serial sectioning focussed on the SLN may detect nests of metastatic cells on HE staining, thereby converting a tumor from Stage I (TxN0M0) to Stage II (TxN1M0). This finding has been noted in 10-15% of cases. However, the prognostic value of micrometastases detected only by immunohistochemical staining or PCR has not been demonstrated. For cancers of the anal canal, SLN biopsy of inguinal nodes has been tested as a means of establishing the indications for inguinal lymph node dissection.

[Not Available]. / Le ganglion sentinelle en pathologie digestive : données actuelles et implications à venir.

M. Pocard, J.-C. Sabourin In theory, the concept of sentinel lymph node (SLN) biopsy can be applied to cancer surgery for all solid cancers. Yet sentinel lymph node biopsy has not become a standard part of gastrointestinal cancer surgery. It has been of value in the assessment of small early-stage gastric cancers, but has only achieved widespread practice in Japan. Studies of SLN biopsy in colon cancer have not shown it to be a reliable predictor of N+ status and therefore don't permit the omission of lymph node dissection in selected cases. On the other hand, as a form of intra-operative lymph node mapping, dye injection of the SLN may demonstrate aberrant lymphatic drainage and could occasionally permit the sparing of a middle colic artery whose sacrifice would otherwise be dictated by standard drainage patterns. SLN biopsy may have prognostic usefulness by demonstrating micrometastases; careful serial sectioning focussed on the SLN may detect nests of metastatic cells on HE staining, thereby converting a tumor from Stage I (TxN0M0) to Stage II (TxN1M0). This finding has been noted in 10-15% of cases. However, the prognostic value of micrometastases detected only by immunohistochemical staining or PCR has not been demonstrated. For cancers of the anal canal, SLN biopsy of inguinal nodes has been tested as a means of establishing the indications for inguinal lymph node dissection.

Efficacy of adjuvant chemotherapy according to Prion protein expression in patients with estrogen receptor-negative breast cancer.

BACKGROUND: Prion protein (PrPc) has been previously reported to be associated with resistance to proapoptotic stimuli. We evaluated whether the expression of PrPc was associated with the resistance to adjuvant chemotherapy in patients with estrogen receptor (ER) -negative breast cancer. PATIENTS AND METHODS: The expression of PrPc by primary tumors was assessed by immunohistochemistry in a series of 756 patients included in two randomized trials that compared anthracycline-based chemotherapy to no chemotherapy. The PrPc expression was correlated with ER expression and the benefit of adjuvant chemotherapy was assessed according to PrPc expression in patients with ER-negative tumors. RESULTS: Immunostaining analysis showed that PrPc was mainly expressed by myoepithelial cells in normal breast tissue. Tissue microarray analysis from 756 breast tumors showed that PrPc was associated with ER-negative breast cancer subsets (P < 0.001). Adjuvant chemotherapy was not associated with a significant risk reduction for death in patients with ER-negative/PrPc-positive disease [adjusted hazard ratio (HR) for death = 0.98, 95% confidence interval (CI) 0.45-2.1, P = 0.95], while it decreased the risk for death (HR = 0.39, 95% CI 0.2-0.74, P = 0.004) in patients with ER-negative/PrPc-negative tumors. CONCLUSION: These data indicate that ER-negative/PrPc-negative phenotype is associated with a high sensitivity to adjuvant chemotherapy.

[Tumour sequencing: Evolutions and revolutions]. / Séquençage des tumeurs : évolutions et révolutions.

For some years now, we have entered the genomic age of tumour genotyping from a medical point of view. Technological breakthroughs in both biology and information science now allow a genomic analysis of cancers in everyday medical practice with, in some case, a major impact on patient care not only for the choice of therapy (i.e. EGFR mutations in lung adenocarcinoma), but also for diagnosis and monitoring of the disease. Tumour genotyping is performed from formalin-fixed paraffin-embedded tissues used for diagnosis of cancer. However, new approaches have emerged, with for example the more and more spread use of "liquid biopsies". Genotyping of a gene panel implicated in carcinogenesis is now routinely performed in some cancer types, with the help of high-throughput sequencers, and it is likely that improvement of these machines will make tumour genotyping easier and more accessible in the near future. Nevertheless, the current challenge is not anymore detection of molecular alterations, but their relevant interpretation, so as to be the most useful in patient care.

Inhibin B is the major form of inhibin/activin family secreted by granulosa cell tumors.

Both experimental and clinical studies suggest that inhibin plays a critical role in the development of granulosa cell tumors (GCT), a subgroup of malignant ovarian tumors. Inhibin has been proposed as a biological marker for the follow-up of patients bearing these particular tumors. Hitherto, there is no general agreement on the molecular form(s) of the inhibin family that are secreted by malignant granulosa cells. Using specific and sensitive immunoassays for activin A and for inhibins A and B, we investigated the production of these molecules in patients with either an adult GCT (n=13) or an epithelial ovarian cancer (n=11). Results showed that serum activin A level was increased in all patients, independently of their clinical status (progressive disease or remission) in comparison to that observed in the healthy pre- and postmenopausal women. Most of the patients also presented a moderate increase in serum inhibin A level compared to that in controls. Only one of eight patients with a progressive granulosa cell tumor had a high value of serum inhibin A. In contrast, serum inhibin B was dramatically increased in eight of nine patients with a granulosa cell tumor and its level correlated with the clinical status of the patients. No correlation was found between the level of serum inhibin B and that of serum antimüllerian hormone, a recently described specific and reliable marker for GCT. None of the patients with an epithelial ovarian cancer presented an increase of serum inhibin B. These observations demonstrate that inhibin B is the major molecular form of the inhibin family proteins produced by malignant granulosa cells.

Identification of pro-EPIL and EPIL peptides translated from insulin-like 4 (INSL4) mRNA in human placenta.

Recently, a new member of the insulin gene superfamily termed insulin-like 4 (INSL4) was identified in the human placenta and uterus. The present study investigated whether placenta translates INSL4 mRNA into a putative peptide named early placenta insulin-like (EPIL). Among antibodies elicited against the C chain of pro-EPIL, one antibody (AB7381) was specifically directed against the C chain 59-88 portion, and among those elicited against the A and B chains of EPIL, one antibody (Ab1661) was directed against the A chain 115-139 and the B chain 23-52 portions. Immunohistochemistry based on antibody 7381 to pro-EPIL and antibody 1661 to EPIL demonstrated that the cytotrophoblast from early placenta preferentially expresses the pro-EPIL peptide, whereas the EPIL peptide is expressed by both the cytotrophoblast and the syncytiotrophoblast. At term, the pro-EPIL peptide was detected in villous cytotrophoblast cells, whereas the EPIL peptide was not detected. Moreover, in vitro experiments performed on term placenta showed that the steady state levels of INLS-4 mRNA in the cytotrophoblast are 10 times (one log unit) lower than in the differentiated villous syncytiotrophoblast cells. Taken together, these findings reveal that expression of EPIL peptides in the villous cytotrophoblast is different from that displayed by the syncytiotrophoblast. Finally, these data are the first demonstration that INSL4 mRNA are translated into pro-EPIL and EPIL peptides.

Screening for multiple endocrine neoplasia type 1 and hormonal production in apparently sporadic neuroendocrine tumors.

Screening was performed in 130 consecutive patients with apparently sporadic neuroendocrine tumors (NET) to assess the prevalence of multiple endocrine neoplasia type 1 (MEN1) and hormonal production. Screening for MEN1 included measurement of serum calcium and PTH [PTH-(1-84)], gastrin, PRL, and insulin-like growth factor type I (IGF-I) levels. MEN1 genetic testing was performed in patients with two components of the MEN1 syndrome. Screening for hormonal production included measurement of serum neuron-specific enolase (NSE), calcitonin (CT), glycoprotein alpha-subunit (GP alpha), hCG beta-subunit (free hCG beta), and somatostatin levels. Twenty-four-hour urinary free cortisol (UFC) and 5-hydroxyindolacetic acid (5-HIAA) determinations were also performed. Four patients had hyperparathyroidism, none of whom had pituitary or familial disease. Hyperprolactinemia was compatible with a pituitary disease in one patient. No acromegalic feature or any increase in IGF-I was found. Hypergastrinemia, compatible with an associated pancreatic NET, was found in one patient. Genetic screening of the MEN1 gene was performed in five of the six patients with two components of the MEN1 syndrome. A nonsense mutation (Arg108stop) was identified in the tumor of one patient. Elevated NSE, 5-HIAA, CT, GP alpha, free hCG beta, SMS, and nonsuppressible UFC were found in 47%, 46%, 14%, 19%, 12%, 3%, and 6% of NET patients, respectively. Production of CT, GP alpha, and free hCG beta was highly related to the primary site: all but two of these secretions originated in foregut NET. 5-HIAA secretion was found in 27% of foregut-derived and 85% of midgut-derived NET. In conclusion, MEN1 is a rare event in patients presenting with apparently sporadic NET. It occurred mainly in foregut NET and should be screened for by serum calcium and PTH-(1-84) measurements. Routine hormonal measurements should depend on the primary site. NSE, 5-HIAA, CT, and alphaGP should be routinely measured in foregut-derived NET; only serum NSE and 5-HIAA measurements are recommended in midgut-derived NET.

Antitumour activity of somatostatin analogues in progressive metastatic neuroendocrine tumours.

A few studies have suggested an antitumour activity of somatostatin analogues in neuroendocrine tumours (NET). The aim of this study was to evaluate the antitumour efficacy of somatostatin analogues in patients with documented progressive tumours. 35 consecutive patients with documented tumour progression were treated with somatostatin analogues. Patients were classified into two groups. In Group 1, tumours were progressing rapidly (an increase of 50% or more in the lesion surface area in 3 months) and in Group 2, tumours were progressing more slowly (an increase of less than 50% in the lesion surface area in 3 months but greater than 25% in 6 months). Treatment consisted of subcutaneous (s.c.) octreotide, 100 microg thrice daily for 17 patients, intramuscular lanreotide, 30 mg/every 14 days for 11 patients and for 7 patients both somatostatin analogues were used successively during the follow-up. Primary tumour sites were the small intestine (n=12), pancreas (n=13), lungs (n=5), and other sites (n=5). 18 patients had the carcinoid syndrome with flushing and/or diarrhoea. The median duration of treatment was 7 months. Treatment was discontinued in 3 patients due to side-effects. One patient (3%) achieved a partial response and the disease was stabilised in 20 patients (57%) for a median duration of 11 months (6-48 months). Stabilisation of patients in Group 1 was significantly less frequent at 6 months than that of patients in Group 2 (4/12 and 13/17 respectively, P<0.02). Somatostatin analogue treatment resulted in one partial response (3%) and 20 cases of stabilisation (57%) in 35 patients with progressive NET. A slow tumour growth rate before treatment is predictive of a good response to somatostatin analogues which could be considered an option for first-line treatment.

The doxorubicin-streptozotocin combination for the treatment of advanced well-differentiated pancreatic endocrine carcinoma; a judicious option?

Due to their rarity, only few trials have studied the role of the doxorubicin-streptozotocin (DS) combination in advanced well-differentiated pancreatic endocrine carcinomas (AWDPEC). However, the published results are inconsistent. We reviewed all AWDPEC (5-year period, 45 patients) treated in our institution with the DS combination for: objective response rate (ORR), progression-free survival, overall survival (OS) and toxicity. An ORR of 36% (95% Confidence Interval (CI) 22-49) was obtained, with 16 partial responses (PR). The mean duration of PR was of 19.7 months. Two and 3-year OS rates were 50.2 and 24.4%, respectively. Toxicities were mainly digestive (grade > or =3 vomiting, 13%) and haematological (grade > or =3 neutropenia, 24%). Previous systemic chemotherapy and malignant hepatomegaly were associated with a poorer ORR (P=0.033, P=0.016) and OS (P=0.008, P=0.045). Multivariate analysis demonstrated previous chemotherapy as the only independent predictive-factor for survival (P=0.013). In conclusion, our data confirm the sensitivity of AWDPEC to the DS combination, with an ORR of 36% and a remarkable median response duration of 19.7 months, and suggests that it could be considered as a valid option in first-line therapy.