Pregnancy-associated plasma protein-A (PAPPA) promotes breast cancer progression.

Breast cancer is the most common malignancy in females and poses a significant health threat to women. Pregnancy-associated plasma protein-A (PAPPA) is highly expressed in pregnancy-associated breast cancer (PABC) tissues. In this study, we investigated the functional role of PAPPA in regulating the malignant phenotype of breast cancer. We first examined the expression level of PAPPA in PABC tissue and breast cancer cell lines using quantitative real-time polymerase-chain reaction (qRT-PCR) and western blot. Next, the functional role of PAPPA in breast cancer cells was validated by overexpression and knockdown experiments. Cell counting kit-8 (CCK-8) proliferation assay, 5-ethynyl-2'-deoxyuridine (EdU) incorporation assay, wound healing and transwell invasion assay were used to examine cell proliferation, migration, and invasion ability. We further identified the microRNA target regulating PAPPA and studied its functional role. Finally, we examined the impact of PAPPA on the tumorigenesis and metastasis of breast cancer in mice model. Our study revealed that PAPPA was upregulated in PABC tissues and breast cancer cells. Overexpression of PAPPA promoted cell proliferation, motility, invasion, and epithelial-mesenchymal transition (EMT). We further identified miR-497-5p as a negative regulator of PAPPA, which suppressed cell proliferation, migration, invasion, and EMT in breast cancer cells. We also validated the oncogenic role of PAPPA in the mouse xenograft model. Collectively, our study suggests that PAPPA is an oncogenic protein highly expressed in PABC tissues and promotes breast cancer progression, which could serve as a novel therapeutic target for breast cancer.

The rarest of rare cases within the one thousand faces of atypical carcinoid: Pseudomesotheliomatous manifestation in a pregnant woman.

Carcinoid tumors in pregnant women are rare, and there have been no previous studies of atypical carcinoid tumor reported in pregnancy. Also, pseudomesotheliomatous manifestation in atypical carcinoid is an extremely rare finding, there being only two cases reported. Here, we present the first case of pseudomesotheliomatous manifestation of atypical carcinoid in a pregnant woman. Upon image analysis, we found that atypical carcinoids with multiple metastatic lesions can exhibit variability in vascularity and metabolism, resulting in heterogeneous image characteristics among metastatic lesions, even those with identical histology. In addition, even with extensive metastasis, patients can exhibit good performance explained by long-standing presentation of indolent cancer.

Heregulin (HRG) assessment for clinical trial eligibility testing in a molecular registry (PRAEGNANT) in Germany.

BACKGROUND: Eligibility criteria are a critical part of clinical trials, as they define the patient population under investigation. Besides certain patient characteristics, clinical trials often include biomarker testing for eligibility. However, patient-identification mostly relies on the trial site itself and is often a time-consuming procedure, which could result in missing out on potentially eligible patients. Pre-selection of those patients using a registry could facilitate the process of eligibility testing and increase the number of identified patients. One aim with the PRAEGNANT registry (NCT02338167) is to identify patients for therapies based on clinical and molecular data. Here, we report eligibility testing for the SHERBOC trial using the German PRAEGNANT registry. METHODS: Heregulin (HRG) has been reported to identify patients with better responses to therapy with the anti-HER3 monoclonal antibody seribantumab (MM-121). The SHERBOC trial investigated adding seribantumab (MM-121) to standard therapy in patients with advanced HER2-negative, hormone receptor-positive (HR-positive) breast cancer and HRG overexpression. The PRAEGNANT registry was used for identification and tumor testing, helping to link potential HRG positive patients to the trial. Patients enrolled in PRAEGNANT have invasive and metastatic or locally advanced, inoperable breast cancer. Patients eligible for SHERBOC were identified by using the registry. Study aims were to describe the HRG positivity rate, screening procedures, and patient characteristics associated with inclusion and exclusion criteria. RESULTS: Among 2769 unselected advanced breast cancer patients, 650 were HER2-negative, HR-positive and currently receiving first- or second-line treatment, thus potentially eligible for SHERBOC at the end of current treatment; 125 patients also met further clinical eligibility criteria (e.g. menopausal status, ECOG). In the first/second treatment lines, patients selected for SHERBOC based on further eligibility criteria had a more favorable prognosis than those not selected. HRG status was tested in 38 patients, 14 of whom (36.8%) proved to be HRG-positive. CONCLUSION: Using a real-world breast cancer registry allowed identification of potentially eligible patients for SHERBOC focusing on patients with HER3 overexpressing, HR-positive, HER2-negative metastatic breast cancer. This approach may provide insights into differences between patients eligible or non-eligible for clinical trials. TRIAL REGISTRATION: Clinicaltrials, NCT02338167 , Registered 14 January 2015 - retrospectively registered.

Diagnosis and treatment of advanced HER2-positive breast cancer in young pregnant female: A case report.

RATIONALE: The incidence of pregnancy-associated breast cancer (PABC) is increasing nowadays, and its diagnosis and treatment remain complicated due to the consideration of the fetus. The available data on PABC are primarily derived from case reports since there are ethical restrictions on conducting randomized clinical trials. In the present work, we reported a case of the human epidermal growth factor receptor 2 (HER2)-positive PABC and described the diagnosis and treatment for such type of breast cancer. PATIENT CONCERNS: A 27-year-old patient was admitted to our hospital with the complaints of right breast mass for 3 days, and she was a first-time pregnant woman with a single live intrauterine fetus at 26 + 3 weeks of gestation. Physical examination of the right breast revealed a palpable and hard mass with obscure boundaries (5.0 cm × 4.0 cm) in the upper outer quadrant. Significant axillary lymph nodes (2.0 cm) were also present. DIAGNOSIS: PABC. INTERVENTION: To protect the fetus, breast ultrasonography was used to test her breast mass, a core needle biopsy was adopted to confirm the diagnosis, and abdominal ultrasound and chest X-ray were used to evaluate the metastasis. The patient was scheduled for neoadjuvant therapy using bi-weekly pirarubicin in combination with cyclophosphamide (AC) without anti-HER2 therapy for consideration of the fetus's safety. After 4 cycles of AC, the patient delivered a healthy male infant. After the delivery, all the treatments were carried out according to the standard recommendation for HER2 + breast cancer as non-pregnant patients. OUTCOMES: After the surgery, the disease-free survival for the patient was 12 months until brain metastasis was diagnosed. She was still undergoing second-line anti-HER2 therapy and currently in a stable situation. Besides, the child was also healthy so far. LESSONS: The methods for the diagnosis and treatment of PABC that result in teratogenesis should be avoided to protect the fetus. Mammogram and chest X-ray were safe approaches for the fetus. Moreover, chemotherapy-based on pirarubicin in combination with cyclophosphamide had no risk to the fetus.

Inflammatory myofibroblastic tumors associated with the placenta: a series of 9 cases.

Inflammatory myofibroblastic tumors (IMTs) of the uterus are often associated with pregnancy and are delivered with the placenta. We describe the clinical, pathologic, and molecular findings in nine cases of placenta-associated IMT (PaIMT). All the lesions were incidentally discovered at delivery or on placental pathological examination. The maternal age ranged from 21 to 41 (mean = 30.6) years. Eight patients had high-risk pregnancies, and when known, all patients were multigravida. Macroscopically, eight tumors were well defined, ranging in size from 2 to 6 cm present at the maternal surface of the placenta (n = 3) and membranes (n = 4) or separately delivered with the placenta (n = 2). All nine lesions revealed classical IMT morphology with spindle cells associated with a lymphoplasmacytic infiltrate and thin elongated vessels. Five showed decidualization, and five showed coagulative necrosis. All tumors expressed CD10. Of the seven tumors that were anaplastic lymphoma kinase (ALK) positive, six were confirmed to have an ALK rearrangement by fluorescence in situ hybridization (FISH), whereas one failed FISH testing. Fusions included TIMP3-ALK (n = 3), THBS1-ALK (n = 2), and a novel SYN3-ALK fusion (n = 1). Clinical follow-up was available in three patients, with no recurrence reported. There appears to be an increased frequency of uterine IMTs in pregnancy and associated with the placenta. No PaIMT has behaved aggressively, although follow-up has been quite limited. This may speak to a specific behavior of these tumors when associated with pregnancy.

Pregnancy-induced Cushing's syndrome with an adrenocortical adenoma overexpressing LH/hCG receptors: a case report.

BACKGROUND: Pregnancy-induced Cushing's syndrome (CS) with an adrenocortical adenoma overexpressing luteinizing hormone (LH)/human choriogonadotropin (hCG) receptors (LHCGR) has been rarely reported in the literatures. This peculiar condition challenges the canonical diagnosis and management of CS. CASE PRESENTATION: A 27-year-old woman (G2P0A1) presented at 20 weeks gestational age (GA) with overt Cushingoid clinical features. Adrenocorticotropic hormone (ACTH)-independent CS was diagnosed based on undetectable ACTH and unsuppressed cortisol levels by dexamethasone. Magnetic resonance imaging (MRI) scanning without contrast revealed a left adrenal nodule while pituitary MRI scanning was normal. A conservative treatment strategy of controlling Cushingoid comorbidities was conducted. At 36 weeks GA, a caesarean operation was performed and a live female infant was delivered. At 8 weeks after parturition, our patient achieved normalization of blood pressure, blood glucose, serum potassium, and urinary cortisol level spontaneously. During non-pregnancy period, stimulation testing with exogenous hCG significantly evoked a cortisol increase. The woman underwent resection of the adrenal tumor at 6 months after parturition. Immunohistochemistry (IHC) showed the tumor tissue that stained positive for luteinizing hormone (LH)/human choriogonadotropin (hCG) receptor (LHCGR), whereas negative for both melanocortin 2 receptor (MC2R) and G protein-coupled receptor-1 (GPER-1). CONCLUSIONS: Stimulation test with exogenous hCG after parturition is necessary for the diagnosis of pregnancy-induced CS. LHCGR plays an essential role in the pathogenesis of this rare condition.

Clinical features and survival of pregnancy-associated breast cancer: a retrospective study of 203 cases in China.

BACKGROUND: Pregnancy-associated breast cancer (PABC) is an aggressive disease, and since Chinese authority began to encourage childbearing in 2015, the incidence of PABC has increased. This study investigated the characteristics and survival of PABC patients. METHODS: Patients with PABC who underwent surgery at Fudan University, Shanghai Cancer Center between 2005 and 2018 were enrolled. Data concerning the tumor characteristics, maternal state (whether first or non-first pregnancy) and survival outcome were recorded. Pearson Chi-square tests were used to compare the characteristics of the tumors, and Kaplan-Meier methods were used to perform the survival analysis. RESULTS: Overall, 203 PABC patients were recruited. Since 2015, 65.5% of non-first pregnant women were diagnosed with breast cancer, it's 5.7 fold of the incidence of PABC in non-first pregnant women. No significant differences in tumor characteristics were observed between the patients who were in their first pregnancy and those in non-first pregnancy. Among the entire PABC population, luminal B breast cancer accounted for the largest proportion (38.4%), followed by triple-negative breast cancer (TNBC, 30.0%). The distribution of the molecular subtypes of PABC and non-PABC differed (P < 0.001) as follows: in the PABC patients, Luminal B 38.4%, Triple negative breast cancer (TNBC) 30.1%, Human Epidermal Growth Factor Receptor 2 (HER-2) overexpression 15.8%, and Luminal A 10.8%; in the non-PABC patients, Luminal A 50.9%, Luminal B 20.1%, TNBC 17.4%, and HER-2 overexpression 8.0%. The 3-year disease free survival (DFS) of all PABC patients was 80.3%. The 3-year DFS of the patients in the first-pregnancy group was 78.4%, and that of the patients in the non-first-pregnancy group was 83.7% (P = 0.325). CONCLUSIONS: Our study proved that the proportion of women who developed PABC during the second or third pregnancy was extremely high relative to the newborn populations. The patients in the PABC population tended to present more luminal B and TNBC breast cancer than the non-PABC patients.

A Narrative Review of Placental Contribution to Adverse Pregnancy Outcomes in Women With Polycystic Ovary Syndrome.

CONTEXT: Polycystic ovary syndrome (PCOS) is the most common endocrinopathy of reproductive-aged women. In pregnancy, women with PCOS experience increased risk of miscarriage, gestational diabetes, preeclampsia, and extremes of fetal birth weight, and their offspring are predisposed to reproductive and cardiometabolic dysfunction in adulthood. Pregnancy complications, adverse fetal outcomes, and developmental programming of long-term health risks are known to have placental origins. These findings highlight the plausibility of placental compromise in pregnancies of women with PCOS. EVIDENCE SYNTHESIS: A comprehensive PubMed search was performed using terms "polycystic ovary syndrome," "placenta," "developmental programming," "hyperandrogenism," "androgen excess," "insulin resistance," "hyperinsulinemia," "pregnancy," and "pregnancy complications" in both human and animal experimental models. CONCLUSIONS: There is limited human placental research specific to pregnancy of women with PCOS. Gestational androgen excess and insulin resistance are two clinical hallmarks of PCOS that may contribute to placental dysfunction and underlie the higher rates of maternal-fetal complications observed in pregnancies of women with PCOS. Additional research is needed to prevent adverse maternal and developmental outcomes in women with PCOS and their offspring.

Breast cancer, placenta and pregnancy.

BACKGROUND: Breast cancer is one of the most frequently diagnosed malignancies during pregnancy. Tumours often present characteristics of high malignancy and are hormone receptor negative/HER2 positive or triple negative. In general, pregnancy, including the postpartum period, is associated with a transiently increased risk of developing breast cancer but followed by a long-lasting protective period. Placental metastases are very rare and, thus far, breast cancer metastases in the foetal compartment have not been described. To discuss these apparently contradictory observations, this narrative review resumes immunological and hormonal alterations during pregnancy potentially affecting breast cancer risk as well as tumour growth and behaviour. OBSERVATIONS: Upregulation of breast cancer-associated genes involved in immunological and reproductive processes has been observed in parous women and is potentially responsible for a transiently increased risk in pregnancy. In contrast, maternal immunisation and immunoglobulin production against antigens expressed on trophoblast cells, such as specific glycosylation patterns of mucin-1 or RCAS1-associated truncated glycans, seem to prevent breast cancer development in later years. Animal and human studies indicate that T cells are involved in these processes. Several placenta-derived factors, especially kisspeptin, have direct anti-tumour effects. The pregnancy-related increase of estrogen, progesterone, and other hormones influence growth and characteristics of breast cancer while the role of further placenta-secreted factors is still controversially discussed. CONCLUSION: Several factors and cells are involved in altered breast cancer risk during and after pregnancy and have potential for developing novel treatment strategies in future.

Preliminary results of identification and quantification of paclitaxel and its metabolites in human meconium from newborns with gestational chemotherapeutic exposure.

OBJECTIVE: Cancer diagnosis during pregnancy occurs in 1 out of 1000 pregnancies with common malignancies including breast and hematological cancers. Fetal exposure to currently utilized agents is poorly described. We directly assessed fetal exposure by screening meconium from 23 newborns whose mothers had undergone treatment for cancer during pregnancy. STUDY DESIGN: Meconium was collected from newborns whose mothers were diagnosed with cancer during pregnancy and underwent chemotherapy in the second or third trimester as part of the Cancer and Pregnancy Registry. We conducted screening of 23 meconium samples for chemotherapeutics and known metabolites of chemotherapeutics by liquid chromatography-high resolution mass spectrometry (LC-HRMS). Putative identification of paclitaxel and/or its metabolites was made in 8 screened samples. In positively screened samples, we quantified paclitaxel, 3'-p-hydroxypaclitaxel, and 6α-hydroxypaclitaxel by stable isotope dilution-LC-HRMS. RESULTS: Mean (standard deviation) levels of paclitaxel in positively screened samples were 399.9 (248.6) pg/mg in meconium samples from newborn born to mothers that underwent chemotherapy during pregnancy. 3'-p-hydroxypaclitaxel and 6α-hydroxypaclitaxel mean levels were 105.2 (54.6) and 113.4 (48.9) pg/mg meconium, respectively. CONCLUSION: Intact paclitaxel, 3'-p-hydroxypaclitaxel, and 6α-hydroxypaclitaxel were detected in meconium, providing unambiguous confirmation of human fetal exposure. Variability in meconium levels between individuals may indicate a potential for reducing fetal exposure based on timing, dosing, and individual characteristics. This preliminary study may provide an approach for examining the effects of cancer diagnosis during pregnancy on other outcomes by providing a measure of direct fetal exposure.

Behavior and Outcomes of Pregnancy Associated Breast Cancer

Introduction: Pregnancy Associated Breast cancer (PABC) is associated with poor prognosis and a decreased overall survival. A retrospective review was conducted to review the experience and outcome in a tertiary care hospital, and to compare those seen in a matched group for year of diagnosis. Materials and Methods: This is a retrospective review of a prospectively collected breast cancer registry. The study was conducted in a tertiary care hospital in Riyadh, Saudi Arabia from January to Decamber 2014 . Female patients with PABC were identified and matched with similar cohort of non-pregnant breast cancer patients that were diagnosed between 2001-2010. Clinical data including age, tumor biology, clinical stage, follow up and outcomes (disease free survival, DFS) were analyzed and compared between the two groups using SAS 9.3 and R-2.14.1 Results: A total of 110 patients in Group 1 and 114 patients in Group II were analyzed. In both groups, the patient age ranged was between 20 to 45 years; the median follow up was 34 months in PABC and 54 months in non-pregnant cohort. PABC were statistically more likely to be triple negative (p value-0.05) and diagnosed at advanced stage (stage 3 and 4) (p value-0.02). There was no difference in the occurrence of Her-2 positive disease. In pregnant patients there was a 5-year survival rate of 65% compared to non-pregnant cohort of 82% with p value of 0.002 and DFS was also 47.5% versus 65.4% with a p value .002 which is statistically significant. Conclusion: Pregnancy associated breast cancer (PABC) is diagnosed at a more advanced stage and tends to be triple negative and they are associated with a worse DFS and overall survival. Early detection during pregnancy may improve outcome.

Chemotherapy in pregnancy: exploratory study of the effects of paclitaxel on the expression of placental drug transporters.

Introduction The use of paclitaxel in pregnant cancer patients is feasible in terms of fetal safety, but little is known about the effects of paclitaxel on the placenta. Using three experimental models, we aimed to assess the effects of paclitaxel on the expression of placental drug transporters. Methods In the in vitro model (human primary trophoblast culture), trophoblasts were isolated from normal term placentas and subsequently exposed to paclitaxel. The transcriptional regulation of 84 genes encoding for drug transporters, and the protein expression of ABCB1/P-gp and ABCG2/BCRP were assessed. In the in vivo model, placental tissues isolated from pregnant cancer patients treated with paclitaxel were analyzed to assess the protein expression of ABCB1/P-gp and ABCG2/BCRP. The same parameters were assessed in extracts from human placental cotyledons perfused ex vivo with paclitaxel. Results In the in vitro model, the expression of twelve drug-transporters genes was found to be significantly down-regulated after exposure to paclitaxel, including ABCC10, SLC28A3, SLC29A2, and ATP7B (involved in the transport of taxanes, antimetabolites, and cisplatin, respectively). The protein expression of ABCB1/P-gp increased by 1.3-fold after paclitaxel administration. Finally, the protein expression of ABCB1/P-gp and ABCG2/BCRP was higher in cotyledons from mothers treated with multiple doses of paclitaxel during pregnancy than in cotyledons perfused with a single dose of paclitaxel. Discussion Paclitaxel modulates the expression of placental drug transporters involved in the disposition of various anticancer agents. Further studies will be needed to assess the impact of repeated or prolonged exposure to paclitaxel on the expression and function of placental drug transporters.

Optimal timing of delivery for women with breast cancer, according to cancer stage and hormone status: a decision-analytic model.

OBJECTIVE: To compare strategies for the timing of delivery in women with breast cancer and known cancer stage or hormone receptor subtype, and to determine the optimal gestational age for induction in regards to maternal-fetal outcomes. STUDY DESIGN: A decision-analytic model was designed comparing eight different strategies for scheduled delivery at 30, 31, 32, 33, 34, 35, 36, and 37 weeks gestation. Optimal breast cancer treatment was assumed to be delayed until after delivery. Baseline estimates of the stage- and subtype-specific mortality and the impact of delayed cancer treatment on 5-year survival rates were obtained from the literature. Outcomes factored into the model included the risk of intrauterine fetal demise, spontaneous delivery, respiratory distress syndrome, cerebral palsy, and neonatal demise at each gestational age. Univariate sensitivity analyses and Monte Carlo simulations were performed to test the robustness of our model. RESULTS: For women with stage I-II breast cancer, delivery at 36 weeks yielded the highest number of overall quality-adjusted life years (QALYs), while maternal QALYs were maximized with delivery at 34 weeks. For stage III and IV disease, maternal QALYs were maximized at 31 and 30 weeks, respectively. For women with estrogen or progesterone receptor-positive, human epidermal receptor-2 negative breast cancer, both maternal QALYs and overall QALYs were maximized with delivery at 36 weeks. More aggressive biological phenotypes were similarly associated with optimal delivery at decreasing gestational age. Our model was heavily driven by the baseline probability of maternal death within 5 years, in addition to the expected progression of disease and decreases in survival rates with each week of non-treatment, and remained robust across reasonable ranges for all variables of interest. CONCLUSIONS: For women with breast cancer diagnosed during pregnancy, decisions regarding timing of delivery should take into consideration both cancer stage and hormone receptor subtype.

Pregnancies during and after trastuzumab and/or lapatinib in patients with human epidermal growth factor receptor 2-positive early breast cancer: Analysis from the NeoALTTO (BIG 1-06) and ALTTO (BIG 2-06) trials.

BACKGROUND: Limited data exist on the safety of using anti-human epidermal growth factor receptor 2 (HER2) targeted agents during pregnancy. To date, only retrospective studies have assessed the prognosis of patients with a pregnancy after prior early breast cancer, with no data in HER2-positive patients. METHODS: The Neoadjuvant Lapatinib and/or Trastuzumab Treatment Optimization (NeoALTTO) trial and the Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization (ALTTO) trial were randomized phase 3 trials for patients with HER2-positive early breast cancer. In both trials, pregnancy information was prospectively collected. Pregnancy outcomes were compared between patients unintentionally exposed to trastuzumab and/or lapatinib during gestation (the exposed group) and those who became pregnant after trastuzumab and/or lapatinib completion (the unexposed group). In the ALTTO trial, disease-free survival (DFS) was compared between pregnant patients and those aged 40 years or younger without a subsequent pregnancy via an extended Cox model with time-varying covariates to account for a guarantee-time bias. RESULTS: Ninety-two patients (12 in the exposed group and 80 in the unexposed group) had a pregnancy: 7 in the NeoALTTO trial and 85 in the ALTTO trial. Seven patients (58.3%) in the exposed group and 10 patients (12.5%) in the unexposed group opted for an induced abortion; in the unexposed group, 10 patients (12.5%) had a spontaneous abortion. No pregnancy/delivery complications were reported for the remaining cases, who successfully completed their pregnancy, with the exception of 1 fetus with trisomy 21 (Down syndrome). No significant difference in DFS (adjusted hazard ratio, 1.12; 95% confidence interval, 0.52-2.42) was observed between young patients with a pregnancy (n = 85) and young patients without a pregnancy (n = 1307). CONCLUSIONS: For patients with HER2-positive early breast cancer, having a pregnancy after treatment completion appears to be safe without compromising fetal outcome or maternal prognosis.

Venous thromboembolism and women's health.

The prevention and treatment of venous thromboembolism (VTE) poses distinct gender-specific challenges. Women of childbearing age are at an increased risk of VTE secondary to the transient risk factors of combined hormonal contraception (CHC) and pregnancy. Cancers specific to women are associated with a significant burden of VTE; whilst the incidence of VTE in localised breast cancer is 5 per 1000 person-years, more cases are seen due to the prevalence of breast cancer. Treatment of VTE in women can be complicated by abnormal uterine bleeding, now increasingly reported with direct oral anticoagulants (DOACs) as well as vitamin K antagonists. Divergence between international guidelines regarding the use of CHC following an oestrogen-associated VTE and appropriate withdrawal of such contraception requires clarification for clinicians. Additionally, there is uncertainty as to whether to consider such events provoked or unprovoked and, consequently, the optimal duration of treatment in these women remains unclear. During pregnancy and the puerperium, the traditional anticoagulants remain the agents of choice with no further advances in DOAC safety data, and similarly in lactation. Further studies evaluating the safety and optimal treatment strategies in these women are awaited.

Immunohistochemistry of p16 in nevi of pregnancy and nevoid melanomas.

BACKGROUND: Hormonal changes in pregnancy are known to alter melanocytic lesions, with some nevi noted to have increased mitotic figures and increased Ki-67 proliferation index. Additionally, cytomorphologic changes have also been noted, referred to as superficial micronodules of pregnancy. These changes may alarm the pathologist for malignancy, particularly nevoid melanoma. Immunohistochemistry for p16 has been recently utilized to distinguish benign nevi from melanoma. We assessed the use of p16 immunohistochemistry for distinguishing melanocytic nevi of pregnant patients from nevoid melanomas. METHODS: Fourteen nevomelanocytic lesions were obtained from pregnant or postpartum patients along with 20 nevoid melanomas for comparison. Immunohistochemistry with p16 was performed on each melanocytic lesion. The percentage of nuclear p16 staining of dermal melanocytes was grouped on a scale of <5%, 5% to 25%, >25% to 50%, and >50%. RESULTS: The majority of nevi from pregnant patients (81%) showed staining of >5% for p16. In contrast, the majority of nevoid melanomas (65%) had staining of <5% for p16. CONCLUSION: The application of p16 as a potential immunohistochemistry diagnostic marker to distinguish nevi from pregnant patients vs nevoid melanomas may be useful.

A comparative analysis of immune privilege in pregnancy and cancer in the context of checkpoint blockade immunotherapy.

Despite their abilities to elicit immune responses, both syngeneic tumors and the half-mismatched placenta grow in the host, unlike a tissue allograft that is aggressively rejected. This is because of local and systemic factors that contribute to the immunologic privilege of tumors and the placenta. Checkpoint blockade immunotherapies subvert this privilege, with spectacularly beneficial outcomes in subsets of patients with certain types of cancer. A challenge for the community of scientists and clinicians is to replicate these successes in pregnant patients with cancer, without harm to the placenta. Here we compare and contrast the immunology of cancers and the placenta, and suggest that immunotherapy for pregnant patients with cancer may be a reasonable option, but that this should be explored systematically.