Later-Line and Salvage Chemotherapy in ACC

Systemic Therapy Backbone

Later-line and salvage chemotherapy in adrenocortical carcinoma (ACC) refers to cytotoxic treatment used after progression on, intolerance of, or unsuitability for standard first-line systemic therapy, most commonly etoposide, doxorubicin, cisplatin, and mitotane (EDP-M). Within the broader ACC treatment pathway, it is part of management for advanced, recurrent, unresectable, or metastatic disease when curative-intent surgery is not feasible and when local therapies alone are unlikely to provide durable control.¹²³

The evidence base for this setting is limited. Unlike first-line treatment, later-line chemotherapy in ACC has not been defined by randomized comparative trials, and most available data derive from phase II studies, retrospective cohorts, narrative reviews, and isolated case reports.⁴⁵¹ As a result, estimates of benefit are imprecise, cross-study comparisons are difficult, and apparent differences between regimens may reflect selection effects rather than true superiority.

Across published series, later-line chemotherapy appears to offer modest antitumor activity for a subset of patients, with disease stabilization more common than objective radiographic response and progression-free intervals typically measured in months rather than years.⁴⁵⁶ Durable remissions are uncommon, although occasional prolonged responses have been reported.⁷ In practice, this places salvage chemotherapy in a predominantly palliative role, where expected benefit must be balanced against toxicity, prior treatment burden, alternative local or investigational approaches, and patient goals of care.¹²

Clinical Context After First-Line Failure

Advanced ACC is usually biologically aggressive, with frequent recurrence and metastatic spread even after prior local treatment. EDP-M remains the best-supported first-line cytotoxic regimen for unresectable or metastatic disease, but no similarly validated standard exists once progression occurs.¹³ Decisions after first-line failure are therefore individualized according to disease tempo, prior exposures, performance status, endocrine burden, and the feasibility of surgery, ablation, or radiotherapy.

This context is important because later-line chemotherapy is generally considered when standard options for durable control have narrowed. Compared with resection in highly selected patients with limited recurrent disease, salvage chemotherapy is less likely to achieve prolonged control; compared with supportive care alone, it may provide temporary stabilization or symptom relief in selected patients, but with a low probability of major tumor shrinkage.² This broad framing is relatively consistent across reviews, although the magnitude of benefit remains uncertain because direct comparative data are lacking.¹²

Common Cytotoxic Approaches

Gemcitabine-Based Regimens

Gemcitabine-based therapy, usually combined with capecitabine or metronomic 5-fluorouracil and often administered with continued mitotane, is the most consistently described later-line cytotoxic strategy in ACC.⁴⁸⁵ Reviews commonly identify it as one of the best-supported post-EDP-M options, but this status reflects the relative scarcity of alternatives rather than strong proof of comparative efficacy.¹²

Across prospective and retrospective reports, gemcitabine-fluoropyrimidine regimens show low objective response rates and more frequent short-term stable disease than tumor shrinkage, with median progression-free survival generally remaining short.⁴⁵⁶ This pattern is probably reliable as a description of modest activity, but it does not establish superiority over other salvage regimens because study populations, prior treatments, and outcome definitions vary substantially.⁴⁵ Clinically, gemcitabine-based therapy is best understood as a reasonable default later-line cytotoxic option when further treatment is desired and tolerability is acceptable.

Streptozotocin and Other Historical Options

Streptozotocin-based therapy remains part of the historical and contemporary later-line treatment landscape and continues to be cited in reviews as a plausible option after first-line failure, often alongside ongoing mitotane.¹² However, the supporting evidence is also limited, and no post-progression cytotoxic regimen has clearly demonstrated a survival advantage in randomized comparisons.

Other historical or off-label cytotoxic-sparing salvage approaches have generally shown little convincing activity. Thalidomide, for example, appears to have minimal efficacy in heavily pretreated refractory ACC and is better regarded as an exceptional measure than a routine choice.⁹ The more reliable conclusion is therefore not that one salvage regimen is clearly best, but that available options have broadly constrained efficacy and are chosen largely on the basis of prior toxicity, patient fitness, and clinician experience.¹²

Outcomes and Patterns of Benefit

The dominant outcome pattern in later-line ACC chemotherapy is limited but sometimes clinically meaningful disease control. Non-comparative studies suggest that a minority of patients achieve temporary non-progression, while median progression-free and overall survival after starting salvage treatment remain short, reflecting both resistant disease biology and the advanced stage at which these regimens are used.⁴⁵⁶

This level of benefit is clearly less than what is sought from effective first-line treatment and generally does not approach the potential durability seen after complete resection in selected recurrent cases. Even so, short-term stabilization may matter when symptoms are driven by tumor bulk or hormonally active disease and when other anticancer options are limited.²³ The practical implication is that treatment goals should usually emphasize palliation, delay of progression, and symptom management rather than expectation of major remission.

Rare prolonged responses indicate that chemosensitivity in ACC is heterogeneous and that aggregate response rates do not capture all individual outcomes.⁷ However, such reports are not reliable for estimating routine benefit because case reports are strongly affected by selection and publication bias. They mainly support the narrower conclusion that exceptional benefit may occur, not that it can be predicted confidently in practice.⁷

Clinical Factors Associated With Benefit

Retrospective data suggest that baseline clinical condition may influence outcomes with salvage chemotherapy. Poor performance status and adverse inflammatory markers, including an elevated neutrophil-to-lymphocyte ratio, have been associated with shorter progression-free survival in gemcitabine-treated cohorts.⁶ These associations are clinically plausible and may help frame prognosis, but they are not validated predictive biomarkers for selecting one regimen over another. In practice, they support cautious patient selection rather than biomarker-driven sequencing.

Toxicity and Practical Limitations

Reported toxicity of later-line chemotherapy is often described as manageable at the cohort level, but treatment burden remains important in patients who are frequently heavily pretreated and clinically vulnerable.⁴⁵ Hematologic toxicity, fatigue, gastrointestinal adverse effects, dose interruptions, and the pharmacologic complexity of concomitant mitotane may all limit treatment delivery.⁴² This is a relatively reliable observation across series, even though exact toxicity rates vary by regimen and patient selection.

Rare but serious complications also shape the risk-benefit balance. Gemcitabine-associated thrombotic microangiopathy has been reported in ACC and may present with hypertension, hemolysis, thrombocytopenia, renal injury, and other systemic manifestations.¹⁰ The existence of this complication is well established, but its incidence in ACC is not well defined; clinically, this means that monitoring and early recognition remain important, particularly because expected oncologic benefit is usually modest.¹⁰

Role in Current Management and Research

Taken together, the available literature places later-line chemotherapy in ACC as a fallback rather than a firmly standardized treatment tier. It may be reasonable for patients with preserved performance status who want additional anticancer therapy after first-line failure, especially when surgery, locoregional therapy, or trial participation are not suitable.¹² For other patients, supportive care, endocrine symptom control, or individualized local treatment may be more appropriate than further cytotoxic therapy.

This limited therapeutic role also highlights a broader evidence gap in advanced ACC. Later-line chemotherapy remains a practical benchmark for comparison with newer targeted or immune-based strategies, but current sequencing decisions continue to rely mainly on retrospective and phase II data rather than robust comparative trials.¹²³

Noncytotoxic Salvage Approaches

Although not conventional chemotherapy, noncytotoxic salvage therapies are sometimes considered in the same post-progression setting. Limited retrospective evidence suggests that multikinase inhibitors may occasionally produce disease control in selected heavily pretreated patients, whereas PD-1 inhibitor monotherapy has shown limited activity overall.¹¹ These findings are hypothesis-generating rather than practice-defining, and their main implication is that such approaches remain individualized or investigational options when standard cytotoxic choices have been exhausted.¹¹

Included Articles

• PMID 18427761: In a patient with metastatic adrenocortical carcinoma treated sequentially with EAP chemotherapy and then gemcitabine monotherapy, gemcitabine was associated with thrombotic microangiopathy presenting with severe hypertension, hemolytic anemia, thrombocytopenia, renal injury, and transient bilateral vision loss. The report emphasizes stopping the causative drug and supportive management, while noting limited evidence for plasmapheresis or glucocorticoids in chemotherapy-associated cases.¹⁰

• PMID 20410174: This multicenter phase II study evaluated gemcitabine plus metronomic 5-fluorouracil or capecitabine with continued mitotane as second- or third-line therapy in heavily pretreated advanced ACC. The regimen showed modest activity with a 4-month non-progression rate of 46.3%, median time to progression of 5.3 months, median overall survival of 9.8 months, and generally manageable toxicity.⁴

• PMID 20583342: A phase II study in heavily pretreated advanced ACC suggested that gemcitabine combined with metronomic fluoropyrimidines can provide second- or third-line clinical benefit, with responses or disease stabilization seen by 4 months and generally acceptable tolerability. The report highlights the scarcity of effective post-platinum, post-mitotane options.⁸

• PMID 29092062: In a multicenter retrospective series of 145 patients with advanced ACC, gemcitabine-based chemotherapy, usually combined with capecitabine and often with mitotane, showed modest activity with median progression-free survival of 12 weeks, partial response in 4.9%, and stable disease in 25.0%, while grade 3-4 toxicity occurred in 11.0% of cases.⁵

• PMID 30469158: This review addresses management after first-line failure in advanced ACC, noting EDP-mitotane as the phase III-supported standard for unresectable disease and summarizing second-line systemic options, with the strongest available data for gemcitabine plus capecitabine or streptozotocin, usually alongside mitotane.¹

• PMID 32303972: This review summarizes systemic treatment options for advanced ACC after progression on first-line therapy. It highlights gemcitabine plus capecitabine or streptozotocin, with or without mitotane, as the best-supported second-line choices based on limited phase 2 and non-comparative data, while emphasizing modest efficacy and short progression-free survival.²

• PMID 33163922: This case report describes metastatic ACC progressing after first-line EDP-mitotane that achieved marked liver metastasis shrinkage and durable disease control for 16 months with second-line gemcitabine, capecitabine, and mitotane. It also notes that evidence for later-line chemotherapy remains limited, with gemcitabine-based regimens offering occasional prolonged responses despite low overall response rates.⁷

• PMID 33163923: For advanced ACC, EDP-mitotane is described as the accepted first-line regimen based on improved progression-free survival versus streptozotocin-mitotane. After progression, second-line treatment remains poorly established, but gemcitabine-capecitabine-mitotane may offer disease control in selected patients, with overall modest response data.³

• PMID 33716976: In metastatic ACC treated with second-line gemcitabine plus capecitabine alongside ongoing mitotane, activity was modest, with 30% clinical benefit at 4 months, median progression-free survival of 3 months, and disease-specific survival of 8 months. Poor baseline ECOG performance status and neutrophil-to-lymphocyte ratio of 5 or higher independently predicted shorter progression-free survival.⁶

• PMID 30428495: A retrospective ENSAT registry analysis of 27 heavily pretreated patients found that thalidomide was generally tolerable but had very limited activity in refractory ACC, with only 2 cases of temporary stable disease and no objective responses. The report supports framing thalidomide as an exceptional salvage measure rather than a standard later-line approach.⁹

• PMID 32666013: A retrospective single-center series of advanced ACC reported occasional responses to late-line multikinase inhibitors, including one prolonged partial response, while PD-1 inhibitor therapy showed limited activity overall. The study supports noncytotoxic salvage treatment as an individualized, investigational option rather than an established standard.¹¹

References

Footnotes

1. Advanced Adrenocortical Carcinoma - What to do when First-Line Therapy Fails?. Exp Clin Endocrinol Diabetes. 2019. PMID: 30469158. Local full text: 30469158.md ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹

2. Advanced Adrenocortical Carcinoma (ACC): a Review with Focus on Second-Line Therapies.. Horm Cancer. 2020. PMID: 32303972. Local full text: 32303972.md ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹²

3. Editorial Comment to Advanced adrenocortical carcinoma successfully treated with gemcitabine plus capecitabine as second-line chemotherapy.. IJU Case Rep. 2020. PMID: 33163923. Local full text: 33163923.md ↩ ↩² ↩³ ↩⁴ ↩⁵

4. Gemcitabine plus metronomic 5-fluorouracil or capecitabine as a second-/third-line chemotherapy in advanced adrenocortical carcinoma: a multicenter phase II study.. Endocr Relat Cancer. 2010. PMID: 20410174. Local full text: 20410174.md ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

5. Gemcitabine-Based Chemotherapy in Adrenocortical Carcinoma: A Multicenter Study of Efficacy and Predictive Factors.. J Clin Endocrinol Metab. 2017. PMID: 29092062. Local full text: 29092062.md ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

6. Clinical Prognostic Factors in Patients With Metastatic Adrenocortical Carcinoma Treated With Second Line Gemcitabine Plus Capecitabine Chemotherapy.. Front Endocrinol (Lausanne). 2021. PMID: 33716976. Local full text: 33716976.md ↩ ↩² ↩³ ↩⁴ ↩⁵

7. Advanced adrenocortical carcinoma successfully treated with gemcitabine plus capecitabine as second-line chemotherapy.. IJU Case Rep. 2020. PMID: 33163922. Local full text: 33163922.md ↩ ↩² ↩³ ↩⁴

8. Cancer: Second-line therapy for adrenocortical carcinoma proves beneficial.. Nat Rev Endocrinol. 2010. PMID: 20583342. Local full text: 20583342.md ↩ ↩²

9. Treatment of Refractory Adrenocortical Carcinoma with Thalidomide: Analysis of 27 Patients from the European Network for the Study of Adrenal Tumours Registry.. Exp Clin Endocrinol Diabetes. 2019. PMID: 30428495. Local full text: 30428495.md ↩ ↩²

10. [A 42 year old patient with bilateral loss of sight and hypertension. Gemcitabine-associated thrombotic microangiopathy (TMA)].. Internist (Berl). 2008. PMID: 18427761. Local full text: 18427761.md ↩ ↩² ↩³

11. Salvage Therapy With Multikinase Inhibitors and Immunotherapy in Advanced Adrenal Cortical Carcinoma.. J Endocr Soc. 2020. PMID: 32666013. Local full text: 32666013.md ↩ ↩² ↩³