In the face of the profound challenges and disruptions linked to the COVID-19 pandemic in 2020, our teams around the world demonstrated incredible resilience, determination and commitment to patients.
We are pleased to announce that we delivered 3.0% in Group sales growth, driven by our strong oncology portfolio. We also expanded our Core Operating margin to 32% of net sales and have set our 2021 guidance: 4.0% Group sales growth and a Core Operating margin of at least 30.0%, excluding any potential impact of incremental investments in external innovation. For more details about our financial results, you can find the full press release here.
These results also highlight the strong foundation on which we will build out our new Group strategy which reinforces our purpose by putting patients and society at the heart of everything we do: Focus. Together. For patients & society.
We look forward to implementing our new Group strategy and achieving ambitious new goals in 2021.