Patterns of Invasion of Cervical Adenocarcinoma as Predicators of Outcome

Pattern A endocervical adenocarcinomas with ovarian metastasis are indolent and molecularly distinct from destructively invasive adenocarcinomas

AIMS

The invasive pattern in HPV-associated endocervical adenocarcinoma (HPVA) has prognostic value. Non-destructive (pattern A) HPVA has excellent prognosis mirroring adenocarcinoma in-situ (AIS). However, the rare occurrence of ovarian spread in these tumours suggests aggressiveness in a subset of patients with these otherwise indolent lesions. We hypothesise that AIS/pattern A HPVA with ovarian metastases are biologically different than metastatic destructively invasive HPVA.

METHODS AND RESULTS

Samples from patients with HPVA and synchronous or metachronous metastases were retrieved and reviewed to confirm diagnosis and determine the Silva pattern in the primary lesion. For each case, normal tissue, cervical tumour and at least one metastasis underwent comprehensive sequencing using a 447-gene panel. Pathogenic single-nucleotide variants and segmental copy-number alterations (CNA), tumour mutational burden and molecular signatures were evaluated and compared between primary and metastases and among invasive pattern categories. We identified 13 patients: four had AIS/pattern A primaries, while nine had pattern B/C tumours. All AIS/pattern A lesions had metastasis only to ovary; 50% of patients with ovarian involvement, regardless of invasive pattern, also had involvement of the endometrium and/or fallopian tube mucosa by HPVA. In the ovary, AIS/pattern A HPVA showed deceptive well-differentiated glands, often with adenofibroma-like appearance. Conversely, pattern C HPVAs consistently showed overt infiltrative features in the ovary. Sequencing confirmed the genetic relationship between primary and metastatic tumours in each case. PIK3CA alterations were identified in three of four AIS/pattern A HPVAs and three of eight pattern B/C tumours with sequenced metastases. Pattern C tumours showed a notably higher number of CNA in primary tumours compared to pattern A/B tumours. Only one metastatic AIS/pattern A HPVA had a novel pathogenic variant compared to the primary. Conversely, five of eight pattern B/C tumours with sequenced metastases developed novel pathogenic variants in the metastasis not seen in the primary. All four AIS/pattern A patients were alive and free of disease at 31, 47, 58 and 212 months after initial diagnosis. Conversely, cancer-related death was documented in five of nine pattern B/C patients with follow-up at 7, 20, 20, 43 and 87 months.

CONCLUSION

Morphologically and genomically, AIS/pattern A HPVA with secondary ovarian involvement appears distinct from destructively invasive tumours. In at least a subset of these cases, ovarian spread appears to occur via trans-Mullerian superficial extension, different from the stromal and lymphatic vascular spread typical of more aggressive tumours (pattern C). These differences may explain the indolent outcome observed in the rare subset of patients with AIS/pattern A HPVA and ovarian metastasis. Our data underscore the potential for conservative surgical management approaches to pattern A HPVA.

Establishment and validation of prognostic nomograms integrating histopathological features in patients with endocervical adenocarcinoma

AIMS

To develop and verify pathological models using pathological features basing on HE images to predict survival invasive endocervical adenocarcinoma (ECA) postoperatively.

METHODS

There are 289 ECA patients were classified into training and validation cohort. A histological signature was produced in 191 patients and verified in the validation groups. Histological models combining the histological features were built, proving the incremental value of our model to the traditional staging system for individualised prognosis estimation.

RESULTS

Our model included five chosen histological characteristics and was significantly related to overall survival (OS). Our model had AUC of 0.862 and 0.955, 0.891 and 0.801 in prognosticating 3-year and 5 year OS in the training and validation cohort, respectively. In training cohorts, our model had better performance for evaluation of OS (C-index: 0.832; 95% CI 0.751 to 0.913) than International Federation of Gynecology and Obstetrics (FIGO) staging system (C-index: 0.648; 95% CI 0.542 to 0.753) and treatment (C-index: 0.687; 95% CI 0.605 to 0.769), with advanced efficiency of the classification of survival outcomes. Furthermore, in both cohorts, a risk stratification system was built that was able to precisely stratify stage I and II ECA patients into high-risk and low-risk subpopulation with significantly different prognosis.

CONCLUSIONS

A nomogram with five histological signatures had better performance in OS prediction compared with traditional staging systems in ECAs, which might enable a step forward to precision medicine.

Patterns and risk factors of recurrence in low-risk early-stage cervical adenocarcinoma treated with surgery alone: implications on risk group stratification

OBJECTIVE

Cervical adenocarcinoma has poorer outcomes compared with squamous cell carcinoma; however, treatment is identical irrespective of histologic sub-types. This study aimed to investigate the patterns and risk factors of recurrence following surgery alone for low-risk early-stage cervical adenocarcinoma.

METHODS

We retrospectively reviewed patients who underwent surgery alone for low-risk early-stage cervical adenocarcinoma between January 2001 and December 2018 in a single institution. Baseline clinicopathological characteristics were collected to identify the factors associated with recurrence-free survival.

RESULTS

A total of 252 patients met the inclusion criteria. Most patients underwent radical hysterectomy (218 patients, 86.5%) and had usual type endocervical adenocarcinoma (190 patients, 75.4%). The International Federation of Gynecology and Obstetrics 2018 stage was IA1 in 72 patients (27.4%), IA2 in 58 (22.1%), IB1 in 51 (19.4%), and IB2 in 71 patients (27.0%). With a median follow-up of 70.4 months (range 6.2-252.5 months), 5-year survival rates were as follows: locoregional recurrence-free survival, 93.0%; recurrence-free survival, 89.6%; overall survival, 94.7%. The recurrence patterns were local in nine patients (32.1%), regional in five patients (17.8%), distant in 10 patients (35.7%), local and distant in one patient (3.6%), regional and distant in two patients (7.2%), and locoregional and distant in one patient (3.6%). In multivariable analysis, negative human papillomavirus (HPV) status (HR 7.314; p<0.001) and deep cervical stromal invasion (HR 5.110; p=0.003) were associated with poor locoregional recurrence-free survival. Patients were stratified based on the number of risk factors and a statistically significant difference in locoregional recurrence-free survival was observed: 5-year survival rates of 99.0%, 84.2%, and 50.0% for patients with 0, 1, and 2 risk factors (0 vs 1, p=0.001; 1 vs 2, p=0.011).

CONCLUSION

Surgery alone for low-risk early-stage cervical adenocarcinoma was associated with favorable outcomes over a long follow-up period. Patients with the highest risk of recurrence were those with a negative HPV status and deep cervical stromal invasion. Additional management following surgery may be considered in patients with these risk factors.

Silva cumulative score and its relationship with prognosis in Endocervical adenocarcinoma

Background

The Silva system has been demonstrated to have a good predictive value of lymph node metastasis (LNM) in endocervical adenocarcinoma (EAC). Tumours were classified based on the highest identified pattern of invasion in this system, this may not exactly reflect the true situation when it presents with a “mixed pattern” in some cases. Recent study has shown that patients with lymphovascular invasion (LVI) have worse prognosis in EAC. Here we design a Silva cumulative score (SCS) system which also combined the LVI status to explore its prognostic role in EAC patients.

Methods

A total of 120 patients with EAC were included in this study. Clinicopathological characteristics were retrospectively retrieved from the medical records and follow-up data were obtained. The clinicopathological information included age at diagnosis, depth of invasion (DOI), LNM, LVI, Silva classification, and SCS. SCS is a classification system based on the sum score of different Silva pattern which is founded on morphological phenomena. The relationships between the pathological characteristics and prognoses were analyzed.

Results

According to the Silva system, 11 (9.2%), 22 (18.3%) and 87 (72.5%) patients had patterns A, B, and C, respectively. Patients with pattern C had the highest incidence of LVI and LNM (p < 0.05). Although the Kaplan-Meier curves demonstrated that survival decreased with increasing Silva classification for A-C cancers, there was no statistically significant difference [disease-free survival (DFS): p = 0.181; overall survival (OS): p = 0.205]. There were 45 cases presented as mixed-type of Silva patterns. According to the SCS, 23 cases (19.2%) were rated as grade I, 31 cases (25.8%) as grade II and 66 (55.0%) cases as grade III. Patients with SCS grade III had the highest incidence of LVI and LNM (p < 0.05). Kaplan–Meier analysis revealed that patients with higher SCS had significantly shorter DFS and OS than those with lower SCS (p < 0.05). High SCS was an independent predictor of poorer OS and DFS (p < 0.05) in patients with EAC.

Conclusions

The application of the Silva system could effectively predict the LNM of patients and may be helpful in selecting an appropriate surgical procedure. The SCS system we designed showed a good predictive value for DFS and OS in EAC.

International Endocervical Adenocarcinoma Criteria and Classification (IECC): An Independent Cohort With Clinical and Molecular Findings

Recently, the International Endocervical Adenocarcinoma Criteria and Classification (IECC) has reorganized the classification of endocervical adenocarcinomas (ECAs), separating them into human papilloma virus (HPV)-associated (HPVA) and HPVA independent (HPVI) categories. In this study, we sought to revalidate the IECC clinical findings in an independent cohort and assess the mutational differences between HPVA and HPVI ECAs using next generation sequencing. Consecutive cases of ECAs were reclassified under the IECC. Clinicopathologic information was collected and tissue was sent for targeted next-generation sequencing in 33 genes. Associations between HPV status, clinicopathologic parameters and mutation status, with survival were evaluated. The series comprised of 85/100 HPVA (63 HPVA-usual type, 4 villoglandular, 3 mucinous intestinal, 15 mucinous not otherwise specified) and 15/100 HPVI (9 gastric, 4 mesonephric, 1 clear cell, 1 not otherwise specified). HPVA ECAs presented at a lower age (P=0.001), smaller tumor sizes (P=0.011), less margin positivity (P=0.027), less Silva pattern C (P=0.002), and lower FIGO stages (P=0.020). HPVA had superior survival compared with HPVI ECA [overall survival (P=0.0026), disease-specific survival (P=0.0092), and progression-free survival (P=0.0041)]. Factors that correlated with worse prognosis irrespective of HPV status were FIGO stage, positive margins and lymphovascular invasion (P<0.05). TP53 mutations were detected in a significantly higher proportion of HPVIs than HPVAs (P<<0.001). The study revalidates the IECC system by reaffirming the clinical and prognostic differences between HPVA and HPVI ECAs in an independent dataset.

Cervical adenocarcinoma: integration of HPV status, pattern of invasion, morphology and molecular markers into classification

Cervical adenocarcinoma is a heterogenous group of tumours with various aetiologies, molecular drivers, morphologies, response to treatment and prognosis. It has become evident that human papillomavirus (HPV) infection does not drive all adenocarcinomas, and appropriate classification is critical for patient management, especially in the era of the HPV vaccine and HPV-only screening. Identified as one of the most important developments in gynaecological pathology during the past 50 years, the separation of cervical adenocarcinomas into HPV-associated (HPVA) and HPV-independent has resulted in a transformation of the classification system for cervical adenocarcinomas. HPVA has been traditionally subclassified by morphology, such as usual type (UEA), mucinous and villoglandular, etc. However, it has become evident that cell type-based histomorphological classification is not clinically meaningful, and the newly proposed International Endocervical Adenocarcinoma Criteria and Classification (IECC) is a necessary and relevant break from this prior system. Non-HPV-associated adenocarcinomas can be divided by their distinct morphology and molecular genomics with very different responses to standard therapies and potential for future targeted therapies. These include gastric-type, clear-cell, mesonephric and endometrioid adenocarcinomas. So-called 'serous' carcinomas of the cervix probably represent morphological variants of UEA or drop metastases from uterine or adnexal serous carcinomas, and the existence of true cervical serous carcinomas is in question. This review will discuss the advances since WHO 2014, and how HPV status, pattern of invasion as described by Silva and colleagues, histological features and molecular markers can be used to refine diagnosis and prognostication for patients with cervical adenocarcinoma.

Cervical Glandular Neoplasia: Classification and Staging

Endocervical adenocarcinomas (EAs) account for 25% of all primary cervical carcinomas. Approximately 85% of EAs are driven by high-risk human papillomavirus (HPV) infection, the most common of which is the so-called usual type endocervical adenocarcinomas. Non-HPV-driven subtypes harbor distinct clinicopathologic features and prognosis and have been increasingly recognized in recent years, which has led to efforts to improve classification of EA based on clinically relevant and reproducible criteria. This review discusses a recently proposed classification system, the International Endocervical Adenocarcinoma Criteria and Classification, which uniquely integrates morphology, cause/pathogenesis, and biological behavior of HPV and non-HPV-driven subtypes of EA.

Pattern based classification of endocervical adenocarcinoma: a review

While endocervical adenocarcinoma is comprised of several histological subtypes, the most common subtype is human papillomavirus-associated usual type, and management of these tumours is primarily determined by FIGO (International Federation of Gynecology and Obstetrics) stage, a clinically based staging system. Early stage cervical cancer is determined by the pathological evaluation of tumour microscopic measurement (depth of invasion), which can be particularly challenging because of the lack of a defined point of origin. Yet important treatment decisions, cone versus radical surgery, are based on this imperfect system, resulting in overtreatment and related morbidities in many patients for whom it may not be necessary. There is a growing consensus, however, for a more conservative approach, one that reduces morbidity and prevents loss of fertility in these (often young) patients. This movement has been supported, in part, by the development of a morphology based risk stratification system which was devised in order to recognise those tumours that, while invasive, could potentially be treated more conservatively. In this review, we provide the reader with the background and rationale for a more conservative approach in treating endocervical adenocarcinoma, summarise the risk stratification system, and review the system's utility and reproducibility. In addition, we comment on recent updates that attempt to further refine the system. The application of this morphology based classification could help identify a subset of patients with endocervical adenocarcinoma (who would otherwise undergo radical surgery based on FIGO staging alone) that have good clinical outcomes and could be treated more conservatively.

Genomic abnormalities in invasive endocervical adenocarcinoma correlate with pattern of invasion: biologic and clinical implications

The pattern-based classification system for HPV-related endocervical adenocarcinoma, which classifies tumors based on the destructiveness of stromal invasion, is predictive of the risk of nodal metastases and adverse outcome. Previous studies have demonstrated clinically important molecular alterations in endocervical adenocarcinoma, including KRAS and PIK3CA mutations; however, correlation between the molecular landscape and pathological variables including pattern of invasion has not been thoroughly explored. In this study, 20 endocervical adenocarcinomas were classified using the pattern-based classification system and were subjected to targeted sequencing using the Ion AmpliSeq Cancer Hotspot Panel v2 (ThermoFisher Scientific, Waltham, MA, USA) that surveys hotspot regions of 50 oncogenes and tumor suppressor genes. Single-nucleotide polymorphisms were correlated with clinical and pathologic variables including pattern of invasion. Five (25%), six (30%), and nine (45%) cases were classified as patterns A, B, and C respectively. Lymph node metastases, advanced stage at presentation and mortality from disease were exclusively seen in destructively invasive tumors (patterns B or C). Prevalent mutations in the cohort involved PIK3CA (30%), KRAS (30%), MET (15%), and RB1 (10%). Most (94%) relevant genomic alterations were present in destructively invasive tumors with PIK3CA, KRAS, and RB1 mutations seen exclusively in pattern B or C subgroups. KRAS mutations correlated with advanced stage at presentation (FIGO stage II or higher). Our findings indicate that the pattern of stromal invasion correlates with genomic abnormalities detected by next-generation sequencing, suggesting that tumors without destructive growth (pattern A) are biologically distinct from those with destructive invasion (patterns B and C), and that pattern B endocervical adenocarcinoma is more closely related to its pattern C counterpart. The pattern-based classification may be used as a triage tool when considering molecular testing for prognostic or therapeutic purposes.

Architectural overlap between benign endocervix and pattern-A endocervical adenocarcinoma: Are all pattern-A tumors invasive?

Studies on the pattern-based classification for invasive endocervical adenocarcinoma showed that tumors with nondestructive invasion (pattern-A) have a 0% rate of nodal metastases. Our understanding of pattern-A tumors and their distinction from in-situ adenocarcinoma requires further study. Thirteen sections diagnosed independently as pattern-A adenocarcinoma by three gynecologic pathologists, and 14 sections of benign endocervix were selected. Three additional pathologists (reviewers) evaluated a digital image from each section and classified it as pattern-A or benign based on architecture only. To blind the interpretation to cytologic features, nuclei and cytoplasm were obscured using morphometric software (Zen 2011, Carl Zeiss Microscopy, Germany). 13/27 cases (48%; 8 pattern-A, 5 benign) were correctly classified by all reviewers; 19/27 (70%; 10 pattern-A, 9 benign) were correctly classified by ≥2 reviewers. 3/13 pattern-A cases (23%) were interpreted as benign by ≥2 reviewers. Conversely, 5/14 benign cervices (36%) were misinterpreted as pattern-A by ≥2 reviewers. The number of glands per 20× field was higher in pattern-A cases with high reviewer agreement (p=0.004). An abnormal architecture is seen in many pattern-A adenocarcinomas in support of their invasive nature; some, however, have architecture that overlaps with that of benign endocervix thus may actually represent in-situ lesions. Likewise, normal cervix can be architecturally complex and mirror patterns that pathologists would classify as pattern-A if malignant cytologic features were present. Based on this overlap and the nil risk of nodal spread, an emphasis on the non-destructive, rather than the invasive, nature of pattern-A adenocarcinoma is recommended.

[Cervical cancer : Update on morphology]

The World Health Organization (WHO) classification from 2014 differentiates between different subtypes of mucinous adenocarcinoma of the uterine cervix. A gastric subtype was recently described that showed no association with high-risk human papillomavirus (HPV) infections, has a poor prognosis, is mainly diagnosed in women of Asian origin and can occur in patients with Peutz-Jeghers syndrome. Although no clear grading system has been recommended in the WHO classification, it is likely that grading of adenocarcinomas of the uterine cervix will partly be based on the different patterns of invasion. Deep stromal infiltration of macroinvasive carcinomas is defined as an infiltration of >66 % of the cervical stroma. In the near future a maximum tumor size of 2 cm could act as a discriminator for planning of less radical surgery. Parameters of the histopathological report that are relevant for the prognostic assessment as well as the choice of adjuvant treatment and function as quality indicators during certification are described. The histological type of an adenocarcinoma alone is of no predictive or prognostic relevance for patients undergoing primary surgical treatment, neoadjuvant chemotherapy, combined chemo-radiotherapy or treatment with angiogenesis inhibitors. Currently, molecular parameters and biomarkers are of no relevance.