Findings from a recent study published in Cornea assessed treatment preferences for ocular surface squamous neoplasia (OSSN) and evaluated shifts in treatment modalities over the past 20 years.
Give me some background first.
OSSN is an umbrella term encompassing a spectrum of squamous epithelial malignancies that involve the cornea or conjunctiva.
While surgical excision has traditionally been the treatment protocol for OSSN, there has been a paradigm shift due to potential adverse events, such as:
- Risk of recurrence
- Scarring
- Limbal stem cell deficiency
As a result, several alternative therapies have emerged, including 5-fluorouracil (5FU), interferon (IFN)-α2b, and mitomycin C (MMC).
Keep going…
While all three topical therapies are useful due to their high-resolution rates and low recurrence frequencies, MMC has a less favorable side-effect profile: the risk of pain and redness after use as well as the potential for long-term limbal stem cell deficiency, melts, and punctal stenosis.
Combination therapy, which consists of surgical excision followed by adjuvant medical intervention, has also been used with reduced recurrence rates compared with surgical excision alone.
Now, talk about the study.
To understand OSSN management trends amongst corneal specialists, researchers sent an electronic survey to members of The Cornea Society, Ocular Microbiology and Immunology Group (OMIG), and four international corneal specialist listservs.
The questions in the survey covered medical and surgical treatment preferences; results were compared with similar surveys administered in 2003 and 2012.
Findings?
In total, there were 285 respondents to the survey, of which 90% self-reported as corneal specialists.
Interestingly, 78% reported using primary topical monotherapy to treat OSSN compared to 58% in 2012 (P=0.008).
Tell me more about primary monotherapies.
In comparison to 2003, trends in primary monotherapies to manage OSSN shifted as follows:
- Topical IFN increased from 14% to 55% (P<0.0001)
- 5FU increased from 5% to 23% (P<0.0001)
- MMC decreased from 76% to 19% (P<0.0001)
What about trends in the surgical management of OSSN?
From 2003 to 2022, the frequency of performing excision without postoperative adjunctive medical therapy significantly decreased (P<0.0001) from:
- 66% to 26% for lesions <2 mm
- 64% to 12% for lesions between 2-8 mm
- 47% to 5% for lesions >8 mm
Additionally, more clinicians reported initiating topical immuno/chemotherapy without performing a biopsy compared to 2003 (31% vs. 11%, P<0.0001).
Expert opinion?
According to the study authors, the increase in cornea specialists who initiated treatment without performing a biopsy “may reflect the increased reliance on high-resolution anterior segment optical coherence tomography (AS-OCT) in serving as an adjunct to establish a diagnosis of OSSN.”
Limitations?
As most of the surveyed participants self-identified as corneal specialists, the sample may not represent all clinicians who treat OSSN. They also did not include information on the use of adjuvant diagnostic tools (i.e., AS-OCT).
Additionally, clinical features of tumor type, which may impact therapeutic decisions, were not included in the study.
Finally, the survey was administered while IFN was still available in the U.S.—since 2022 IFN is currently not produced in the U.S.—resulting in decreased accessibility for patient care and a potential shift to 5FU as a first-line replacement option.
Take home.
These findings indicate a clear paradigm shift in the treatment protocols and management of OSSN.
And the bigger picture?
On a broader scale, there has been a significant increase in eyecare practitioners employing medical therapy as a first-line approach—specifically topical interferon, but also including 5FU—in lesions of all sizes and a reduction in the frequency of those managing OSSN with surgical excision alone.
Next steps?
The research team noted, “Looking forward, we suspect that increased utilization of deep learning methods as diagnostic tools in ophthalmology will lead to future applications of this technology to help identify and monitor treatment of OSSN.”