Summary: incidence of ACC and of the aggressive subgroup

Population-level incidence data are reported for ACC overall, not for the solid or high-grade transformation subgroup. Reported incidence of ACC is 3 to 4.5 per million, and approximately 1,200 to 1,300 new cases are diagnosed annually in the United States. In the Surveillance, Epidemiology, and End Results (SEER) program, 3,026 head and neck ACC cases were recorded between 1973 and 2007 (mean age at diagnosis 57.4 years), with a decline in incidence over that period. ACC represents 10% to 25% of malignant salivary gland tumors.

No registry reports incidence of aggressive ACC directly. Estimates of the aggressive share come from institutional series: ACC-I accounted for 20 of 54 tumors (37%) in a proteogenomic cohort; high-grade transformation was identified in 23 of 412 ACC cases (5.6%) at a single center in China; and solid-type histology was present in 27.5% of 58 cases at a Japanese institution. Day One Biopharmaceuticals reports that up to 40% of patients have aggressive ACC.

Incidence of ACC overall: rate per million

“ACC is a rare malignant tumor with a reported incidence of 3–4.5 per million” (opens the source at this quote in a new tab)
“It arises mainly from minor and major salivary glands, representing 10–25% of malignant tumors of salivary glands” (opens the source at this quote in a new tab)
“A total of 5150 patients were included (4.2% from the Midwest, 17.2% from the Northeast, 22.5% from the South, and 56.1% from the West regions).” (opens the source at this quote in a new tab)

“It is diagnosed in roughly four per one million people annually, and does not discriminate by ethnicity or lifestyle factors.” (opens the source at this quote in a new tab)

Incidence of ACC overall: annual cases in the United States

“Here, we evaluate the comparative genomic landscapes of primary versus R/M ACC in 1045 sequenced cases, a cohort size that approximates the annual incidence of ACC in the United States (approximately 1200 per year).” (opens the source at this quote in a new tab)

“Annual U.S. incidence of ~1,300 patients, including: ACC-1 subtype Clinically aggressive non-ACC-1” (opens the source at this quote in a new tab)

Incidence trends and age at diagnosis: SEER 1973 to 2007

“The authors identified 3026 patients with ACCHN. The mean age at diagnosis among those cases was 57.4 years (range, 11-99 years). Analyses of incidence data demonstrated a decline in ACCHN rates between 1973 and 2007, noted across all sexes and races with no detectable inflexion points.” (opens the source at this quote in a new tab)

“AdCC can occur at all ages but is most common later in life (Fifth to Sixth decade)” (opens the source at this quote in a new tab)

Frequency of the aggressive subgroup: ACC-I, solid histology, and high-grade transformation

“Cluster I (ACC-I) (20 of 54; [37%]) was enriched for tumors with any solid component” (opens the source at this quote in a new tab)

“Five independent cohorts from two publications comprising 247 patients (90 ACC I, 157 ACC II) were included.” (opens the source at this quote in a new tab)

“Histology was cribriform/tubular type (C-T type) in 62.0% and solid type in 27.5%.” (opens the source at this quote in a new tab)

“A 1:1 match comparison between 23 HGT patients and non-HGT counterparts was extracted from 412 ACC cases, focusing on dissecting distinctive clinicopathological features and prognostic outcomes.” (opens the source at this quote in a new tab)

“Up to 40% of patients have an aggressive form of ACC characterized by solid/basaloid or high-grade transformation histology” (opens the source at this quote in a new tab)

Frequency of high-grade transformation in a consecutive single-center ACC series

“A total of 412 ACCs diagnosed pathologically at Beijing Tongren Hospital between June 2008 and December 2019 were identified, including 23 HGT cases and 389 non-HGT cases.” (opens the source at this quote in a new tab)
“Our study further emphasizes its rarity, as only 23 (5.6%) out of 412 head and neck ACCs exhibited HGT.” (opens the source at this quote in a new tab)
“In ACC, HGT remains an uncommon finding. Less than a hundred cases have been reported in the English literature” (opens the source at this quote in a new tab)
“with the majority being case reports.” (opens the source at this quote in a new tab)

Published cases of high-grade transformation in adenoid cystic carcinoma

“Since the original description of 3 cases of HGT/dedifferentiation in AdCCs (both de novo and in recurrences) by Cheuk et al” (opens the source at this quote in a new tab)
“> 50 cases have now been published.” (opens the source at this quote in a new tab)

Annual cases of ACC diagnosed in the United States

“Each year around 1,600 cases of ACC are diagnosed within the United States (4), typically presenting with locoregional disease.” (opens the source at this quote in a new tab)

Population-based incidence of ACC and share of salivary gland cancers

“A large Danish population-based study estimates that AdCC accounts for 27.9% of the overall incidence of salivary gland cancers (SGCs) (11/1,000,000/year), corresponding to an annual incidence of 3/1,000,000/year” (opens the source at this quote in a new tab)
“In Nova Scotia, the annual incidence raises to 4.5/1,000,000 cases” (opens the source at this quote in a new tab)
“AdCC is the most common cancer in MSGs, where the proportion of AdCC ranges from 32% to 71%.” (opens the source at this quote in a new tab)

Emiltatug ledadotin (Emi-Le)

Incidence of Adenoid cystic carcinoma with solid histology or high-grade transformation