High-risk features in primary versus secondary enucleated globes with advanced retinoblastoma: a retrospective histopathological study

A retrospective study on adjuvant chemotherapy in retinoblastoma: validation of the new recommendation against treatment for pT2a tumors based on the 8th AJCC classification

BACKGROUND

Retinoblastoma (RB) is an intraocular malignant tumor detected in early childhood with variable global impact. Histopathological classification of the tumor in enucleated globes with RB is the key for the decision of adjuvant chemotherapy use. We aim to validate the use of adjuvant chemotherapy in cases with combined pre-laminar/intralaminar optic nerve (ON) invasion and focal choroidal invasion according to the American Joint Committee on Cancer (AJCC) 8th classification.

METHODS

This is a retrospective study conducted at King Abdulaziz University Hospital (KAUH) and King Khalid Eye Specialist Hospital (KKESH) in Riyadh, Saudi Arabia of all RB cases who underwent enucleation over 22 years (2000 to 2021). The histopathological findings were reviewed to identify the enucleated globes classified as pT2a tumors, as an inclusion criterion. Basic demographic and clinical data were collected via chart review Simple descriptive and basic statistical analysis of the data was used where applicable.

RESULTS

Thirty-one patients who had an enucleated globe with RB that fit into the above classification were included. Sixteen were males and 15 were females. The median age was 14 months (IQR = 14 months). Most of the patients (93.5%) had no family history of RB. The commonest presentation was leukocoria in 87.1% followed by squint in 32.3%. Fourteen patients (45.2%) were treated by enucleation alone while 17 patients (54.8%) received adjuvant chemotherapy. Out of these, 7 patients had unilateral RB and the remaining 10 patients had bilateral RB. None of our patients developed recurrence or metastatic disease irrespective of the indication for adjuvant chemotherapy use after a maximum period of follow up reaching 17.84 years and a median of 10.6 years (IQR = 5.92).

CONCLUSIONS

In patients with 8th AJCC histopathological classification of pT2a, chemotherapy following enucleation might not be justified. The outcome in our untreated group of patients did not differ from the treated group with the absence of metastasis after a relatively long period of follow up with a median exceeding 10 years in both groups. Therefore, the risk and benefit of post enucleation adjuvant chemotherapy in the treatment of unilateral RB should be carefully decided and discussed with the primary caregivers taking into consideration the most recent evidence and recommendations in the literature.

Current Indications of Secondary Enucleation in Retinoblastoma Management: A Position Paper on Behalf of the European Retinoblastoma Group (EURbG)

Simple Summary

Although secondary enucleation (SE) is the treatment of choice for retinoblastoma eyes that did not respond favorably to conservative therapies, clear criteria for its indication are, however, currently missing. In this position paper on behalf of the European Retinoblastoma Group (EURbG), we discuss the available literature on SE, including its influence on metastases rate and survival, and propose guidelines to assist decision-making to interrupt eye-preserving therapies depending on the availabilities of advanced diagnostic and therapeutic modalities. Absolute indications to SE may be restricted to eyes with refractory tumor activity resisting all salvage treatments or eyes under apparent tumor control but no visual potential and irreducible complications. In contrast, eyes with an obscured optic nerve head and/or ocular complications amenable to specific surgical or medical management can be considered relative indications, provided that appropriate follow-up can be implemented and that parents are fully aware of a residual risk.

Abstract

Secondary enucleation (SE) puts an irreversible end to eye-preserving therapies, whenever their prolongation is expected to violate the presumed state of metastatic grace. At present, it must be acknowledged that clear criteria for SE are missing, leading to empiric and subjective indications commonly related to disease progression or relapse, disease persistence masking the optic nerve head or treatment-related complications obscuring the fundus view. This absence of evidence-based consensus regarding SE is explained by the continuously moving frontiers of the conservative management as a result of diagnostic and therapeutic advances, as well as by the lack of studies sufficiently powered to accurately stratify the risk of metastasis in conservatively treated patients. In this position paper of the European Retinoblastoma Group (EURbG), we give an overview of the progressive shift in the indications for SE over the past decades and propose guidelines to assist decision-making with respect to when SE becomes imperative or recommended, with corresponding absolute and relative SE indications. Further studies and validation of biologic markers correlated with the risk of metastasis are expected to set more precisely the frontiers of conservative management and thus consensual criteria for SE in the future.

High-risk features in primary versus secondary enucleated globes with advanced retinoblastoma: a retrospective histopathological study

PURPOSE

The management of bilateral advanced retinoblastoma (RB) cases is challenging with attempts to use neoadjuvant therapy salvaging of one of the globes. Our aim in this study was to demonstrate the effect of this primary therapy on the histopathological features and risk factors in secondary enucleated compared to primarily enucleated globes with groups D and E RB.

METHODS

We retrospectively reviewed all enucleated globes with advanced RB received in the pathology laboratories over a period of 5 years. Patients were divided into two groups: one with primary enucleations and another with at least one secondary enucleated globe, and their demographic and clinical data were analyzed. The enucleated globes in the two groups were analyzed to compare the general histopathological features including tumor seeding, size, differentiation, growth pattern, mitotic figures, and focality. More importantly, high-risk features: choroidal invasion, optic nerve (ON) invasion, iris/anterior chamber invasion, ciliary body invasion, and scleral and extra-scleral extension, as well as the pathological classification of the tumor (pT) according to the American Joint Committee on Cancer 7th edition were also compared between the two groups.

RESULTS

We had a total of 106 enucleated globes (78 primary and 28 secondary enucleations) from 99 patients with advanced RB (73 patients with primarily and 26 with secondarily enucleated globes). Demographic and clinical profiles of patients were similar in both, but the mean interval from presentation to enucleation was significantly longer in the secondary enucleations (P = 0.015). Rare/occasional mitotic figures were observed in secondary enucleations using multivariate analysis (P = 0.003). Primarily enucleated globes had higher risk of tumor seeding (P = 0.020), post-laminar/surgical margin ON invasion (P = 0.001), and massive choroidal invasion (P = 0.028). Half of the secondary enucleated globes had tumors confined to the globes without invasion (pT1) and statistically significant lower tumor classifications (pT1 or pT2a) compared to primary enucleations (P =0.001). However, 18% of the secondarily enucleated globes in 3 patients had unfavorable outcome with RB-related mortality after a period of 1-4 years.

CONCLUSIONS

Secondary enucleated globes with advanced RB show favorable histopathological findings mainly less mitosis. These eyes have significantly lower chance for harboring choroidal and ON invasion, thus mostly classified as pT1 or pT2a when compared to primarily enucleated globes. The decision for secondary enucleation was observed to be significantly delayed (8.0 months ± 9.8). Prompt decision for needed enucleation based on the response to primary treatment and careful histopathological examination of enucleated globes are essential to prevent disease-related mortality.