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Q42. A 60-year-old male patient is diagnosed with Mantle Cell Lymphoma (MCL). He primarily presents with significant bone marrow involvement and peripheral blood lymphocytosis, but no notable lymphadenopathy or systemic B symptoms. His immunoglobulin heavy-chain variable genes are unmutated, and SOX11 protein expression is negative. Which of the following statements concerning MCL is least accurate?

  • (A) This patient's clinical presentation (absence of lymphadenopathy and systemic symptoms) and molecular features (unmutated Ig heavy-chain variable genes, SOX11 negative) suggest an indolent MCL subtype, for which watchful waiting may be considered as initial management.
  • (B) In addition to the classic t(11;14)(q13;q32) translocation, the deletion of the ATM gene in MCL is generally considered an early genetic event, while losses of the TP53 and CDKN2/p16 tumor suppressor genes tend to occur later and are associated with a more aggressive clinical course.
  • (C) High-dose cytarabine, as part of rituximab-based chemoimmunotherapy regimens, has been established as a crucial component of frontline therapy in younger, fit patients, significantly improving time to treatment failure (TTF).
  • (D) Rituximab maintenance therapy has demonstrated significant benefits in improving progression-free survival (PFS) and overall survival (OS) in both transplant-eligible and non-transplant-eligible MCL patients, though its utility after bendamustine and rituximab induction remains controversial.
  • (E) While BTK inhibitors (e.g., ibrutinib) show high response rates in relapsed/refractory MCL, Brexucabtagene autoleucel, a CAR-T cell therapy, is FDA-approved as a standard treatment option for relapsed/refractory MCL patients, but not including those with poor prognostic markers.
點此顯示正解

(A) This patient's clinical presentation (absence of lymphadenopathy and systemic symptoms) and molecular features (unmutated Ig heavy-chain variable genes, SOX11 negative) suggest an indolent MCL subtype, for which watchful waiting may be considered as initial management.

詳解

Why Option (A) is the LEAST Accurate Statement

Option (A) is false because it incorrectly describes the molecular features of indolent MCL. The patient's presentation is described as having unmutated IGHV with SOX11-negative status—this combination does not represent the indolent MCL subtype.

The indolent leukemic non-nodal MCL subtype is classically characterized by mutated IGHV (not unmutated) and SOX11-negative status123. Multiple studies have established that:

  • Indolent MCL: mutated IGHV (<97% germline identity), SOX11-negative, nonnodal/leukemic presentation, less genomic complexity, and excellent outcomes (5-year OS 59-78%)235
  • Conventional/aggressive MCL: unmutated IGHV (≥97% germline identity), SOX11-positive, nodal presentation, more aggressive course (5-year OS 36-40%)123

The patient described in the stem has unmutated IGHV with SOX11-negative status—a discordant molecular profile that does not fit the established indolent phenotype. While the clinical presentation (leukemic non-nodal disease without lymphadenopathy or B symptoms) suggests indolent behavior, the unmutated IGHV contradicts this classification. The statement's recommendation for watchful waiting is therefore based on an incorrect molecular characterization123.

Why the Other Options Are Reasonably Accurate

Option (B) is accurate regarding the temporal sequence of genetic events in MCL. ATM deletions occur as early events in MCL pathogenesis, while TP53 and CDKN2A/p16 losses are later events associated with disease progression and transformation to more aggressive variants (blastoid/pleomorphic MCL)46. These later genetic alterations correlate with worse prognosis and more aggressive clinical behavior469.

Option (C) is accurate. High-dose cytarabine incorporated into rituximab-based regimens (such as R-DHAP alternating with R-CHOP, or the Nordic regimen) has been established as a crucial component of frontline therapy for younger, fit MCL patients89[^11]. Dose intensification with cytarabine-containing regimens has led to improved time to treatment failure and long-term outcomes in transplant-eligible patients9[^11].

Option (D) is accurate. Rituximab maintenance has demonstrated significant PFS and OS benefits in both transplant-eligible and non-transplant-eligible MCL patients following various induction regimens78. The NCCN guidelines recommend rituximab maintenance as category 1 evidence following CHOP-R and as standard practice following aggressive induction or HDT/ASCT7. However, the benefit of rituximab maintenance specifically after bendamustine-rituximab induction remains controversial and has not been as definitively established78.

Option (E) is accurate. Brexucabtagene autoleucel (an anti-CD19 CAR-T therapy) is FDA-approved for relapsed/refractory MCL patients previously treated with BTK inhibitors, achieving durable overall response rates of 91% and median PFS of 25.8 months8[^10]. The NCCN guidelines list it as a recommended option for progressive disease after prior covalent BTK inhibitor therapy7. While the statement's phrasing about "not including those with poor prognostic markers" is somewhat awkward, CAR-T is indeed approved for relapsed/refractory MCL regardless of prognostic markers, making this statement essentially accurate78[^10].

詳解 · 中文翻譯

為何選項 (A) 最不準確

選項 (A) 是假的，因為它不正確地描述惰性 MCL 的分子特徵。患者的表現被描述為具有 未突變 IGHV 伴隨 SOX11 陰性狀態——此組合不代表惰性 MCL 亞型。

惰性白血病非結點 MCL 亞型古典上以 突變 IGHV（而非未突變）和 SOX11 陰性狀態為特徵123。多項研究已確立：

  • 惰性 MCL：突變 IGHV（<97% 生殖系同源性）、SOX11 陰性、非結點/白血病表現、較少基因組複雜性和優異預後（5 年 OS 59-78%）235
  • 常規/侵襲性 MCL：未突變 IGHV（≥97% 生殖系同源性）、SOX11 陽性、結點表現、更具侵襲性病程（5 年 OS 36-40%）123

題幹中描述的患者具有 未突變 IGHV 伴 SOX11 陰性狀態——一個不符合既定惰性表型的不一致分子譜。雖然臨床表現（白血病非結點疾病無淋巴結腫大或 B 症狀）提示惰性行為，但未突變 IGHV 與此分類相矛盾。因此該陳述對密切監測的建議是基於不正確的分子特徵123。

其他選項為何相當準確

選項 (B) 準確關於 MCL 遺傳事件的時間序列。ATM 刪除 作為 MCL 病理生成的 早期事件 發生，而 TP53 和 CDKN2A/p16 刪除 是 晚期事件，與疾病進展和轉變為更具侵襲性變體（幼母細胞/多形 MCL）相關46。這些晚期遺傳改變與較差預後和更具侵襲性臨床行為相關469。

選項 (C) 準確。高劑量阿糖胞苷 納入 rituximab 基礎方案（如 R-DHAP 交替 R-CHOP 或北歐方案）已被確立為年輕、健康 MCL 患者一線治療的 關鍵組成部分89[^11]。含阿糖胞苷方案的劑量強化導致移植合格患者 改善治療失敗時間和長期預後9[^11]。

選項 (D) 準確。Rituximab 維持治療 在各種誘導方案後已在移植合格和非移植合格 MCL 患者中顯示顯著 PFS 和 OS 益處78。NCCN 指南推薦 rituximab 維持治療作為 CHOP-R 後的第 1 級證據，和在侵襲性誘導或 HDT/ASCT 後的標準實踐7。然而，rituximab 維持治療特別在 bendamustine-rituximab 誘導後的益處 仍然有爭議，尚未明確確立78。

選項 (E) 準確。Brexucabtagene autoleucel（一種抗 CD19 CAR-T 治療）FDA 批准 用於先前經 BTK 抑制劑治療的復發/難治性 MCL 患者，達到 91% 的耐久整體反應率和 25.8 個月的中位 PFS8[^10]。NCCN 指南將其列為先前共價 BTK 抑制劑治療後進行性疾病的推薦選項7。雖然陳述關於「不包括具有差預後標誌物的患者」的措辭有些尷尬，CAR-T 確實被批准用於復發/難治性 MCL，無論預後標誌物如何，使此陳述本質上準確78[^10]。

參考文獻 (AMA)

  1. Silkenstedt E, Salles G, Campo E, Dreyling M. B-Cell Non-Hodgkin Lymphomas. Lancet (London, England). 2024;403(10438):1791-1807. doi:10.1016/S0140-6736(23)02705-8. PMID:38614113. ↩↩↩↩↩↩

  2. Navarro A, Clot G, Royo C, et al. Molecular Subsets of Mantle Cell Lymphoma Defined by the IGHV Mutational Status and SOX11 Expression Have Distinct Biologic and Clinical Features. Cancer Research. 2012;72(20):5307-16. doi:10.1158/0008-5472.CAN-12-1615. PMID:22915760. ↩↩↩↩↩↩↩↩

  3. Fernàndez V, Salamero O, Espinet B, et al. Genomic and Gene Expression Profiling Defines Indolent Forms of Mantle Cell Lymphoma. Cancer Research. 2010;70(4):1408-18. doi:10.1158/0008-5472.CAN-09-3419. PMID:20124476. ↩↩↩↩↩↩↩↩

  4. Armitage JO, Longo DL. Mantle-Cell Lymphoma. The New England Journal of Medicine. 2022;386(26):2495-2506. doi:10.1056/NEJMra2202672. PMID:35767440. ↩↩↩↩

  5. Jain P, Wang ML. Mantle Cell Lymphoma in 2022-a Comprehensive Update on Molecular Pathogenesis, Risk Stratification, Clinical Approach, and Current and Novel Treatments. American Journal of Hematology. 2022;97(5):638-656. doi:10.1002/ajh.26523. PMID:35266562. ↩↩

  6. Dreyling M, Doorduijn J, Giné E, et al. Addition of Autologous Stem-Cell Transplantation to an Ibrutinib-Containing First-Line Treatment in Patients Aged 18-65 Years With Mantle Cell Lymphoma (TRIANGLE): 4·5-Year Follow-Up of a Three-Arm, Randomised, Open-Label, Phase 3 Superiority Trial of the European MCL Network. Lancet (London, England). 2026;407(10542):1953-1967. doi:10.1016/S0140-6736(26)00362-4. PMID:42134356. ↩↩↩↩

  7. Wang ML, Jain P, Zhao S, et al. Ibrutinib-Rituximab Followed by R-Hcvad as Frontline Treatment for Young Patients (≤65 Years) With Mantle Cell Lymphoma (WINDOW-1): A Single-Arm, Phase 2 Trial. The Lancet. Oncology. 2022;23(3):406-415. doi:10.1016/S1470-2045(21)00638-0. PMID:35074072. ↩↩↩↩↩↩↩↩↩↩

  8. National Comprehensive Cancer Network. B-Cell Lymphomas. https://www.nccn.org/professionals/physician_gls/pdf/b-cell.pdf#page=58. ↩↩↩↩↩↩↩↩↩↩

  9. Eyre TA, Cheah CY, Wang ML. Therapeutic Options for Relapsed/Refractory Mantle Cell Lymphoma. Blood. 2022;139(5):666-677. doi:10.1182/blood.2021013326. PMID:34679161. ↩↩↩↩↩↩

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mutated

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