Predicting rectal cancer tumor budding grading based on MRI and CT with multimodal deep transfer learning: A dual-center study

Objective

To investigate the effectiveness of a multimodal deep learning model in predicting tumor budding (TB) grading in rectal cancer (RC) patients.

Materials and methods

A retrospective analysis was conducted on 355 patients with rectal adenocarcinoma from two different hospitals. Among them, 289 patients from our institution were randomly divided into an internal training cohort (n = 202) and an internal validation cohort (n = 87) in a 7:3 ratio, while an additional 66 patients from another hospital constituted an external validation cohort. Various deep learning models were constructed and compared for their performance using T1CE and CT-enhanced images, and the optimal models were selected for the creation of a multimodal fusion model. Based on single and multiple factor logistic regression, clinical N staging and fecal occult blood were identified as independent risk factors and used to construct the clinical model. A decision-level fusion was employed to integrate these two models to create an ensemble model. The predictive performance of each model was evaluated using the area under the curve (AUC), DeLong's test, calibration curve, and decision curve analysis (DCA). Model visualization Gradient-weighted Class Activation Mapping (Grad-CAM) was performed for model interpretation.

Results

The multimodal fusion model demonstrated superior performance compared to single-modal models, with AUC values of 0.869 (95% CI: 0.761-0.976) for the internal validation cohort and 0.848 (95% CI: 0.721-0.975) for the external validation cohort. N-stage and fecal occult blood were identified as clinically independent risk factors through single and multivariable logistic regression analysis. The final ensemble model exhibited the best performance, with AUC values of 0.898 (95% CI: 0.820-0.975) for the internal validation cohort and 0.868 (95% CI: 0.768-0.968) for the external validation cohort.

Conclusion

Multimodal deep learning models can effectively and non-invasively provide individualized predictions for TB grading in RC patients, offering valuable guidance for treatment selection and prognosis assessment.

Role of tumor budding and fibrotic cancer stroma in head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is an aggressive cancer with an increased frequency of lymph node metastasis at the time of presentation. Tumour budding, characterised by the presence of a single cell or a small grouping of tumour cells (a cluster containing fewer than five malignant cells) at the invasive front and composition of the fibrotic cancer stroma has been demonstrated to have a growing impact on the behaviour of the solid tumour. However exact role played by them is yet to be defined and a standardized scoring system needs to be incorporated.

MATERIAL AND METHODS

A total of 45 histopathologically confirmed cases of HNSCC were included in the study. Hematoxylin and Eosin staining (H&E staining), and immunohistochemistry for CK and alpha-SMA were applied to study the tumour budding and fibrotic cancer stroma in all HNSCC cases. The tumour budding was graded as, Grade 1: 0-4 tumour buds, Grade 2: 5-9 buds and Grade 3: ≥ 10 buds and the nature of fibrotic cancer stroma was categorized as mature, intermediate or immature.

RESULTS

Among 45 cases analyzed, well differentiated squamous cell carcinoma (WDSCC; Grade 1) accounted for 42.22% (19 cases), whereas moderately differentiated squamous cell carcinoma (MDSCC; Grade 2) and poorly differentiated squamous cell carcinoma (PDSCC; Grade 3) comprised 48.89% (22 cases) and 8.89% (4 cases) respectively. Tumour budding showed instances of 0-4 buds in 33.3% (Grade 1), 5-9 buds in 48.9% (Grade 2), and ≥ 10 buds in 17.8% of cases. Evaluating tumour stroma, Intermediate stroma led at 51.1%, Mature at 37.8%, and 11.1% displayed Immature stroma. Histologically, < 5 buds were seen in 47.4% of Grade 1 cases, while ≥ 10 buds were in 75.0% of Grade 3 cases, proven statistically significant (p = 0.021). However, an association between T&N Stage and tumour budding lacked significance. WDSCC notably had more mature stroma than MDSCC and PDSCC, whereas MDSCC showed higher rates of intermediate and immature stroma (p < 0.001). Comparatively, no significant correlation existed between fibrotic stroma and tumour budding (p = 0.076). Also, fibrotic stroma was compared with tumour budding, however, no significant correlation was found (p = 0.076) CONCLUSION: This study reveals a significant link between tumour budding, cancer stroma, and WHO tumour grade. Thus, evaluating these factors in HNSCC cases can serve as valuable histological prognostic indicators, aiding in treatment planning and prognosis assessment.

Can tumour budding change the future of pulmonary adenocarcinoma?

BACKGROUND

Pulmonary adenocarcinoma shows different prognosis even in the same pathological subtype and stage. In this study, it is aimed to investigate the relationship between tumour budding and known prognostic values and clinicopathological features in pulmonary adenocarcinoma.

METHODS

In this study, there have been 77 patients diagnosed with primary pulmonary adenocarcinoma. In the evaluation process, the number of budding between 0 and 4 is accepted as low budding (Bd1), the number of budding between 5 and 9 is considered as medium budding (Bd2), and the number of budding above 10 is considered as high budding (Bd3).

RESULTS

According to the findings of the study, it can be seen that there is a statistical difference between tumour budding and stromal fibrosis (p < 0.001). The presence of pleural invasion, lymph vascular invasion and perineural invasion in patients with Bd3 is found to be statistically higher than the patients with Bd1 (p = 0.048) (p = 0.041) (p = 0.029).

CONCLUSIONS

Tumour budding has been associated with pleural invasion, lymph vascular invasion, perineural invasion, and stromal fibrosis. This study is the first to show the relationship between tumour budding and stromal fibrosis in pulmonary adenocarcinomas. The role of tumour budding in lung cancers remains to be clarified.

Proposal of a grading system for squamous cell carcinoma of the lung - the prognostic importance of tumour budding, single cell invasion, and nuclear diameter

The prognostic markers of lung squamous cell carcinoma (LSCC) are less investigated. The aim of our study was to evaluate tumour budding (TB), minimal cell nest size, nuclear diameter (ND), and spread through air spaces (STAS) among patients with resected LSCC, semi-quantitatively. Furthermore, we aimed to identify a grading system for the best prognostic stratification of LSCC. Patients who underwent surgical resection at the Department of Surgery, University of Szeged between 2010 and 2016 were included. Follow-up data were collected from medical charts. Morphological characteristics were recorded from histologic revision of slides. Kaplan-Meier analysis, log rank test and Cox proportional-hazards model, ROC curve analysis, and intraclass correlation were utilised. Altogether 220 patients were included. In univariate analysis, higher degree of TB, infiltrative tumour border, larger ND, the presence of single cell invasion (SCI) and STAS were associated with adverse prognosis. Based on our results, we proposed an easily applicable grading scheme focusing on TB, ND, and SCI. In multivariate analysis, the proposed grading system (pOS < 0.001, pRFS < 0.001) and STAS (pOS = 0.008, pRFS < 0.001) were independent prognosticators. Compared to the previously introduced grading systems, ROC curve analysis revealed that the proposed grade had the highest AUC values (AUCOS: 0.83, AUCRFS: 0.78). Each category of the proposed grading system has good (ICC: 0.79-0.88) reproducibility. We validated the prognostic impact of TB, SCI, ND, and STAS in LSCC. We recommend a reproducible grading system combining TB, SCI, and ND for proper prognostic stratification of LSCC patients. Further research is required for validation of this grading scheme.

The relationship between primary colorectal cancer histology and the histopathological growth patterns of corresponding liver metastases

Background

The histopathological growth patterns (HGPs) are a prognostic and predictive biomarker in colorectal cancer liver metastasis (CRLM). This study evaluates the relationship between the HGP and primary colorectal cancer (CRC) histopathology.

Methods

A total of 183 treatment-naive patients with resected CRC and CRLM were included. Thirteen CRC histopathology markers were determined and compared between the desmoplastic and non-desmoplastic HGP; tumour sidedness, pT&pN stage, tumour grade, tumour deposits, perineural- (lympho-)vascular- and extramural venous invasion, peritumoural budding, stroma type, CRC growth pattern, Crohn’s-like lymphoid reaction, and tumour-infiltrating lymphocyte (TIL) density. Logistic regression analysis was performed using both CRC and CRLM characteristics.

Results

Unfavourable CRC histopathology was more frequent in non-desmoplastic CRLM for all markers evaluated, and significantly so for a lower TIL density, absent Crohn’s-like lymphoid reaction, and a “non-mature” stroma (all p < 0.03). The cumulative prevalence of unfavourable CRC histopathology was significantly higher in patients with non-desmoplastic compared to desmoplastic CRLM, with a median (IQR) of 4 (3–6) vs 2 (1–3.5) unfavourable characteristics observed, respectively (p < 0.001). Multivariable regression with 9 CRC histopathology markers and 2 CRLM characteristics achieved good discriminatory performance (AUC = 0.83).

Conclusions

The results of this study associates primary CRC histopathology with the HGP of corresponding liver metastases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09994-3.

Molecular mechanisms of tumour budding and its association with microenvironment in colorectal cancer

Colorectal cancer (CRC) is the third most common cancer worldwide. Poor survival of CRC associated with the development of tumour metastasis led to the investigation of the potential biomarkers to predict outcomes in CRC patients. Tumour budding (TB) is a well-known independent prognostic marker for poor survival and disease metastasis. Therefore, it has been suggested that TB status is included in routine clinicopathological factors for risk assessment in CRC. In contrast with a vast majority of studies regarding the prognostic power of TB, there is no clear evidence pertaining to the underlying molecular mechanism driving this phenotype, or an understanding of TB relationship with the tumour microenvironment (TME). The aim of the present study is to present a comprehensive review of TB and tumour cell signalling pathways together with the cross-talk of immune cells that could drive TB formation in CRC.

A novel self-learning framework for bladder cancer grading using histopathological images

In recent times, bladder cancer has increased significantly in terms of incidence and mortality. Currently, two subtypes are known based on tumour growth: non-muscle invasive (NMIBC) and muscle-invasive bladder cancer (MIBC). In this work, we focus on the MIBC subtype because it has the worst prognosis and can spread to adjacent organs. We present a self-learning framework to grade bladder cancer from histological images stained by immunohistochemical techniques. Specifically, we propose a novel Deep Convolutional Embedded Attention Clustering (DCEAC) which allows for the classification of histological patches into different levels of disease severity, according to established patterns in the literature. The proposed DCEAC model follows a fully unsupervised two-step learning methodology to discern between non-tumour, mild and infiltrative patterns from high-resolution 512 × 512 pixel samples. Our system outperforms previous clustering-based methods by including a convolutional attention module, which enables the refinement of the features of the latent space prior to the classification stage. The proposed network surpasses state-of-the-art approaches by 2-3% across different metrics, reaching a final average accuracy of 0.9034 in a multi-class scenario. Furthermore, the reported class activation maps evidence that our model is able to learn by itself the same patterns that clinicians consider relevant, without requiring previous annotation steps. This represents a breakthrough in MIBC grading that bridges the gap with respect to training the model on labelled data.

Systematic review of tumour budding and association with common mutations in patients with colorectal cancer

INTRODUCTION

Despite a well-known prognostic role in colorectal cancer, the genomic profiling of tumour budding remains to be elucidated. We aim to review the association of common mutations with tumour budding.

METHODS

A systematic review of studies relating to tumour budding and genetic mutation in CRC was performed. The relationship between mutational status and tumour budding was evaluated using meta-analysis.

RESULTS

A total of 6153 patients from 17 articles were included. According to the meta-analysis, high-grade tumour budding was significantly associated with KRAS mutation (OR = 1.52, 95 %CI: 1.13-2.02, P = 0.005) and MSS/pMMR (OR = 2.06, 95 %CI: 1.42-2.97, P = 0.0001).

CONCLUSION

The significant association between high-grade tumour budding and mutated KRAS or MSS/pMMR may suggest a role of these mutations in the development of the tumour budding phenotype and be useful for stratifying patient outcome in CRC.

Pattern and Significance of Tumour Budding in Colorectal Carcinomas Using ITBCC Guidelines: a Low Resource Setting Practice Observation

PURPOSE

To determine the pattern and significance of tumour budding among colorectal carcinoma (CRC) Nigerian patients using the 2016 International Tumour Budding Consensus Conference (ITBCC) guidelines.

METHODS

H&E-stained slides of resected CRC at the University College Hospital and a private laboratory, both in Ibadan, Nigeria, from January 2008 to December 2017 were reviewed. Patient age, gender, tumour size and location were obtained from the surgical pathology records. Tumours were graded and staged according to the 2010 WHO and the 2017 UICC protocols, respectively. Tumour budding was determined at × 20 objective lens magnification with a 20-mm eyepiece field number diameter. Descriptive, Mann-Whitney U and chi-square test statistics were applied using SPSS 20; p < 0.05 was considered significant.

RESULTS

Ninety-six cases were included in this study. Fifty-one (53.1%) showed tumour budding. Tumour bud count was low (0-4) in 66 (68.8%), intermediate (5-9) in 12 (12.5%) and high (≥ 10) in 18 (18.8%) tumours. Four tumours had pT1 stage, 35 pT2, 37 pT3 and 20 pT4. Forty-three (44.8%) tumours were lymph node-positive, and 10 (10.4%) had metastasis. Patients' age and tumour size distribution were similar in the tumour budding and non-budding groups (52.4 ± 17.1/58.5 ± 13.9 years and 6.6 ± 2.9/6.6 ± 2.8 cm, respectively). There was significant association between tumour budding and tumour grade (p < 0.008), pT stage (p < 0.000), lymphovascular permeation (p < 0.000), perineural invasion (p < 0.003) and nodal status (p < 0.034), but not with gender (p = 0.588), metastasis (p = 0.327) and TNM group-stage (p = 0.062).

CONCLUSION

Tumour budding frequency is high among our CRC patients and is associated with poorer prognostic factors.

Tumour-stroma ratio outperforms tumour budding as biomarker in colon cancer: a cohort study

The tumour-stroma ratio (TSR) and tumour budding (TB) are two high-risk factors with potential to be implemented in the next TNM classification. The aim of the current study was to evaluate the practical application of the two biomarkers based on reproducibility, independency and prognostic value. Patients diagnosed with stage II or III colon cancer who underwent surgery between 2005 and 2016 were included. Both TSR and TB were scored on haematoxylin and eosin-stained tissue sections. The TSR, based on the relative amount of stroma, was scored in increments of 10%. TB was scored following the consensus guidelines; a bud was defined as ≤ 4 tumour cells. For analysis, three categories were used. Cohen's kappa was used for reproducibility. The prognostic value was determined with survival analysis. In total, 246 patients were included. The TSR distribution was N = 137 (56%) stroma-low and N = 109 (44%) stroma-high. The TB distribution was TB-low N = 194 (79%), TB-intermediate N = 35 (14%) and TB-high N = 17 (7%). The reproducibility of the TSR was good (interobserver agreement kappa = 0.83 and intraobserver agreement kappa = 0.82), whereas the inter- and intraobserver agreement for scoring TB was moderate (kappa 0.47 and 0.45, respectively). The survival analysis showed an independent prognostic value for disease-free survival for TSR (HR 1.57; 95% CI 1.01-2.44; p = 0.048) and for TB-high (HR 2.01; 95% CI 1.02-3.96; p = 0.043). Based on current results, we suggest the TSR is a more reliable parameter in daily practice due to better reproducibility and independent prognostic value for disease-free survival.

The histopathological and molecular features of breast carcinoma with tumour budding-a systematic review and meta-analysis

PURPOSE

Tumour budding (TB) is an adverse histological feature in many epithelial cancers. It is thought to represent epithelial-mesenchymal transition, a key step in the metastatic process. The significance of TB in breast carcinoma (BC) remains unclear. The aim of this study is to investigate the relationship between TB and other histological and molecular features of BC.

METHODS

A systematic search was performed to identify studies that compared features of BC based on the presence or absence of high-grade TB. Dichotomous variables were pooled as odds ratios (OR) using the Der Simonian-Laird method. Quality assessment of the included studies was performed using the Newcastle-Ottawa scale (NOS).

RESULTS

Seven studies with a total of 1040 patients (high-grade TB n = 519, 49.9%; low-grade/absent TB n = 521, 50.1%) were included. A moderate to high risk of bias was noted. The median NOS was 7 (range 6-8). High-grade TB was significantly associated with lymph node metastasis (OR 2.32, 95% c.i. 1.77 to 3.03, P < 0.001) and lymphovascular invasion (OR 3.08, 95% c.i. 2.13 to 4.47, P < 0.001). With regard to molecular subtypes, there was an increased likelihood of high-grade TB in oestrogen (OR 1.66, 95% c.i. 1.21 to 2.29, P = 0.002) and progesterone receptor-positive (OR 1.48, 95% c.i. 1.09 to 2.02, P = 0.01) tumours. In contrast, triple-negative breast cancer had a reduced incidence of high-grade TB (OR 0.46, 95% c.i. 0.30 to 0.72, P = 0.0006).

CONCLUSION

High-grade TB is enriched in hormone receptor-positive BC and is associated with known adverse prognostic variables. TB may offer new insights into the metastatic process of BC.

Prognostic significance of peritumoural and intratumoural budding in intestinal-type gastric adenocarcinoma

BACKGROUND AND STUDY AIMS

Tumour budding (TB) at the invasive front, termed peritumoural budding (PTB), is an established prognostic factor for many solid tumours. However, intratumoural budding (ITB) in gastric adenocarcinoma (GAC), which is frequently observed at the tumour centre, particularly in tumour biopsy tissues, remains poorly understood. Hence, we aimed to determine the correlation of ITB with PTB and their connection with clinicopathological characteristics as well as their prognostic value in GAC.

PATIENTS AND METHODS

We investigated a total of 153 cases of GAC wherein tissues were primarily resected and their related clinicopathological data. A continuous series of paraffin-embedded tissues was stained by haematoxylin-eosin staining, and budding cells were identified by immunohistochemical staining. PTB and ITB were counted in five fields with the highest density of tumour buds. The selected area was examined under 40 high-power field. Cases were divided into low-grade TB and high-grade TB groups according to the median bud count.

RESULTS

Among the 153 patients with GAC, 51 underwent simultaneous observation of ITB and PTB, which were found to have a significant positive correlation. A higher grade of ITB in tumours was associated with positive lymph node metastasis and could predict a worse prognosis. Additionally, patients with simultaneous PTB and ITB had a shorter overall survival than those with PTB alone, suggesting a worse prognosis.

CONCLUSION

PTB and ITB were found to be adverse prognostic factors and high-risk indicators of intestinal-type GAC, and ITB plays an important role in evaluating GAC prognosis in gastroscopic biopsy tissues. Additionally, TB might become a useful index for predicting GAC prognosis in the future.

Tumour Budding Is an Independent Predictive Factor of Cutaneous Squamous-cell Carcinoma Aggressiveness

BACKGROUND/AIM

Tumour budding (TB), i.e. the presence of groups of ≤5 tumour cells ahead of the invasive tumour front, is a pathological feature associated with an aggressive outcome in several cancer types. The aim of this study was to assess the value of TB as an independent prognostic factor of cutaneous squamous cell carcinomas (cSCC).

MATERIALS AND METHODS

We studied 25 cases of aggressive cSCC (defined as tumours that developed local recurrences and/or metastases after adequate excision) and 27 cases of non-aggressive cSCC. TB was expressed as the mean number of tumour buds in 5 adjacent high-power fields (HPF).

RESULTS

Statistical analysis showed that TB is an independent predictive factor of cSCC aggressiveness. When the cut-off value of 0.8 buds/HPF was considered, the positive and negative predictive values for cSCC aggressiveness reached 77.3% and 75.0%, respectively.

CONCLUSION

As with other cancer types, TB appears to be a new independent pathological factor of aggressiveness of cSCC, providing a new tool to predict cSCC outcome, similar to other already established features associated with an adverse outcome (such as tumour size).

Tumour budding in preoperative biopsy specimens is a useful prognostic index for identifying high-risk patients in early-stage (pN0) colon cancer

Background/aim

Tumour budding (BD) is considered a valuable prognostic factor in colon cancer (CC), but its use in daily practice is uncertain. We investigated the prognostic effect of BD using preoperative biopsy specimens in a fairly homogeneous population.

Materials and methods

Eighty-two (pN0) CC patients who underwent surgery after preoperative biopsy between 1997 and 2013 were included in the study. Model A (using the ‘deeply invasive blocks & hot-spot area & invasive margin) and method 1 (using the ‘20× objective & immunohistochemistry staining & quantitive counting’) were used as standard methods.

Results

High BD was significantly associated with poor prognostic factors (lymphatic invasion [P = 0.008], perineural invasion [P = 0.041], advanced pT [P = 0.015], invasive margin [P = 0.008], and margin involvement [P = 0.019]). Moreover, correlations between different BD estimates (r = 0.613–0.696), reproducibility of study (Κappa = 0.68–0.73), and usefulness of cut-off value (area of under ROC = 0.746 [0.663–0.829]) were well. In univariate analysis, 5-year survival was poor in patients with high BD (relaps-free survival [RFS]: 71 %, P < 0.001; overall survival [OS]: 73 %, P = 0.004, local recurrence [LR]: 18 %, P = 0.032). Multivariate analyses confirmed that high BD is an independent worse survival parameter for RFS (Hazard ratio [HR]: 1.53 [1.14–2.80], P = 0.015), OS (HR: 1.44 [1.17–2.75], P = 0.032, and LR (HR: 1.59 [1.05–2.76], P = 0.045).

Conclusion

Our data show that BD provides valuable prognostic information for early-stage (pN0) CC in preoperative biopsy specimens and that adding BD to current risk classification may contribute to better patient selection.

Are tumour grade and tumour budding equivalent in colorectal cancer? A retrospective analysis of 771 patients

BACKGROUND

Tumour grade is traditionally considered in the management of patients with colorectal cancer. However, a large body of literature suggests that a related feature, namely tumour budding, may have a more important clinical impact. The aim of our study is to determine the correlation between tumour grade and tumour budding and their impact on patient outcome.

METHODS

A retrospective collective of 771 patients with colorectal cancer were included in the study. Clinicopathological information included tumour grade (World Health Organisation 2010; G1, G2 and G3) and tumour budding evaluated as BD1, BD2 and BD3 and representing 0-4 buds, 5-9 buds and 10 or more buds per 0.785 mm², respectively.

RESULTS

Tumour grade and tumour budding were correlated (p < 0.0001, percent concordance: 33.8%). Of the BD1 cases, 18.1% were of G3. Only two BD3 cases were G1. Both high tumour grade and tumour budding were associated with higher pT, lymph node metastasis, distant metastasis and lymphatic and venous vessel invasion (p < 0.01, all), but only tumour grade was additionally associated with right-sided tumour location and mucinous histology. Higher tumour budding led to worse overall (p = 0.0286) and disease-free survival (p = 0.001), but tumour grade did not. Budding was independent of tumour grade in multivariate analysis.

DISCUSSION

Tumour grade and tumour budding are distinct features, as recognised by their different clinicopathological associations, reflecting different underlying biological processes. Nonetheless, tumour budding seems to outperform tumour grade in terms of predicting disease-free survival.

Tumour Budding and Tumour Stroma Ratio are Reliable Predictors for Death and Recurrence in Elderly Stage I Colon Cancer Patients

AIM

Tumour budding (BD) and Tumour stroma ratio (TSR) are considered valuable survival parameters for colon cancer (CC), but it is still unclear whether these parameters predict a poor prognosis. This study aimed to determine the survival effect of TB and TSR in elderly stage I CC patients.

METHODS

We evaluated these parameters in eighty-eight stage I CC patients who underwent surgical treatment alone between 1998 and 2015. The relationship between these parameters and age was investigated. Model A was used for methodology.

RESULTS

In elderly patients (≥68), these parameters obtained more successful results for following analysis: relationship between prognostic factors [lymphatic invasion (BD, p = 0.003; TSR, p = 0.003), perineural invasion (BD, p = 0.016; TSR, p = 0.004), tumour deposites (BD, p = 0.005; TSR, p = 0.033), MSI (BD, p=0.031; TSR, p=0.012), etc.], correlation of estimates (BD, r=0.724; TSR, r=0.703), and reproducibility of study (BD [Kappa (ĸ)]=0.53-0.75; TSR (ĸ) =0.56-0.71). Also, the cut-off values were useful for BD (area of under ROC (AUC)=0.816 [0.707-0.925]) and TSR (AUC=0.810 [0.697-0.924]). In univariate analysis, in elderly patients, these parameters had a poor 5-year survival for RFS (p<0.001[BD], p=0.001[TSR]), OS (p<0.001[BD], p=0.005[TSR]), and LR (p=0.008[BD], p=0.034[TSR]). Multivariate analysis confirmed that these parameters are independent worse predictors for RFS (BD: 1.42[HR], p=0.002; TSR: 1.50[HR], p=0.001), OS (BD: 1.38[HR], p=0.014; TSR: 1.42[HR], p=0.005), and LR (BD: 1.61[HR], p=0.034) in elderly patients.

CONCLUSIONS

Our results confirm that BD and TSR are reliable indexes for poor survival in elderly stage I CC patients. We recommend using model A for successful results and standardization.

Does heterogeneity matter in the estimation of tumour budding and tumour stroma ratio in colon cancer?

Background

Tumour budding (TB) and Tumour Stroma Ratio (TSR) may be rewarding in the treatment stratification of patients with stage II colon cancer. However, lack of standardization may exclude these parameters from being used in a clinical setting. The purpose of this methodologic study was to compare stereology with semi-quantitative estimations of TSR, to investigate the intra-tumoural heterogeneity of TB and TSR, and to assess the intra- and inter-observer agreement.

Methods

Three paraffin embedded tumour blocks, one of them representing the deepest invasive front, were selected from each of 43 patients treated for stage II colon cancer. TSR was estimated in H&E sections semi-quantitatively using conventional microscopy, and stereologically on scanned slides, using the newCAST stereology platform. TB was scored across 10 high power fields at the invasive front in cytokeratin AE1/AE3 stained sections.

Results

Subjective, semi-quantitative estimates of TSR significantly correlated to the stereological estimates, with the best correlation found for sections with the deepest invasive tumour penetration (σ = 0.621, p < 0.001). Inter-observer agreement was moderate to substantial for both TB (Κappa = 0.46–0.73) and TSR (Κappa = 0.70–0.75).

The Intraclass correlation coefficient (ICC) for TSR varied from 0.322 based on stereological hotspot estimation to 0.648 for the semi-quantitative evaluation. For TB, ICC varied from 0.646 based on continuous data to 0.698 based on categorical data (cut-off: 10 buds). Thus, the intra-tumoural heterogeneity for both TB and the semi-quantitative estimation of TSR was low.

Conclusion

We recommend using only one tissue section representing the deepest invasive tumour area for estimation of TSR. For TB we recommend using one tissue section; however due to low representation of high-budding tumours, results must be considered with caution.

Electronic supplementary material

The online version of this article (10.1186/s13000-018-0697-9) contains supplementary material, which is available to authorized users.

A nationwide population-based study

PURPOSE

High-risk patients with stage II colon cancer (CC) may benefit from adjuvant chemotherapy, but additional prognostic markers are needed for better stratification. We investigated the prognostic value of tumour stroma ratio (TSR) and tumour budding (TB).

METHODS

A nationwide population-based cohort of 573 patients with stage II CC was included. TSR was scored on hematoxylin and eosin sections as low TSR (> 50% stroma) and high TSR (≤ 50% stroma). TB was evaluated in hotspots on pan-cytokeratin stained sections in 10 high power fields (HPF) at the invasive front and classified by the mean number of buds per HPF as high grade budding (≥ 10 buds) or low-grade budding (< 10 buds). The prognostic value was investigated in Cox proportional hazard models for recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Low TSR was associated with worse RFS (HR = 1.342 (95% CI 1.006-1.791), p = 0.045) and OS (HR = 1.376 (95% CI 1.016-1.862), p = 0.039). Furthermore, an association was found between low TSR and microsatellite stabile tumours (p < 0.001). The mean number of buds per HPF was associated to TSR with increasing number of buds related to a lower TSR (p = 0.026). No statistically significant prognostic impact of TB regarding OS or RFS was detected.

CONCLUSIONS

TSR provided valuable prognostic information, and adding TSR to the current risk stratification may contribute to better patient selection. The estimates of TSR and TB were found to be associated, but no prognostic value of TB was documented.

Tumour Budding Correlates with Aggressiveness of Cutaneous Squamous-cell Carcinoma

BACKGROUND/AIM

Tumour budding (TB) is a specific pathological feature that has been found to be associated with an aggressive outcome in several cancer types; however, to our knowledge, TB has not yet been assessed in squamous-cell carcinomas of the skin (SCC). The aim of the study was to study whether TB correlates with aggressiveness in cutaneous SCC.

MATERIALS AND METHODS

We examined 31 aggressive SCC (that later developed local recurrences or metastases) in comparison with 21 non-aggressive SCC (not complicated by recurrence or metastasis). TB was expressed as the mean number of tumour buds in five adjacent high-power fields of each SCC.

RESULTS

Aggressive SCC had a much higher TB score compared to control SCC (1.63±1.35 vs. 0.49±0.9, p<0.001).

CONCLUSION

As with other cancer types, TB seems to be a pathological marker of aggressiveness of cutaneous SCC, along with other features known to be associated with an aggressive outcome (tumour thickness, level of invasion and lymphovascular or perineural invasion). Further studies including a larger number of tumours will hopefully validate TB as a new pathological predictor of aggressiveness in cutaneous SCC and will allow its correlation with other pathological features of SCC aggressiveness to be defined.