Image source: Pfizer, Inc.

After reporting rosy first-quarter financials and increasing its outlook for the year, Pfizer (NYSE:PFE) shares are trading higher. Investors wondering if Pfizer's shares should be bought or sold on this news might want to consider these nine numbers, each of which offers additional insight into whether the company is worth owning in your portfolio.

15%. Ex-out the impact of last year's acquisition of specialty pharma Hospira, and that's the amount Pfizer reported for operational (ex-currency) sales growth. Include Hospira, and sales were up 26% to $13 billion, ex-currency.

$0.67. Realizing greater savings associated with integrating Hospira and leveraging revenue against fixed costs allowed Pfizer to report this amount in adjusted EPS. That handily outpaced industry watchers' $0.55 forecast. Future EPS should benefit from greater Hospira integration tailwinds, too. The company upped its forecast for cost savings from the Hospira acquisition from $800 million to $1 billion by 2018.

$1 billion. Thanks to rapidly growing use of its breast cancer drug Ibrance, the company's global oncology revenue reached this level in Q1. For comparison, Pfizer's global cancer sales totaled only $528 million in the same quarter a year ago.

1,029%. That's the year-over-year increase in global Ibrance sales last quarter. Ibrance clocked in at $429 million in Q1, giving the drug an annualized sales run rate of $1.7 billion. That's a pretty darn good pace for a drug that only hit the market a bit more than a year ago.

$66 million. Pfizer's revenue from biosimilar drugs, or drugs that work similarly to, but aren't exact copies of biologic medicines, came in at this amount in the quarter. Biosimilar sales got a boost from the launch of Inflectra in Europe last February. Inflectra is a biosimilar to the top-selling autoimmune drug Remicade, and its sales could be heading higher in the coming year following FDA approval last month.

$20 billion. This is Pfizer's estimate of the size of the biosimilars market in 2020. Inflectra and seven other candidates the company has in development could make it one of the biggest biosimilar drugmakers on the planet by then.

23.8%. Pfizer's hopes to acquire Allergan plc in an attempt to shift its tax address from the U.S. to low-cost Ireland were dashed by regulators last quarter, but Pfizer did manage to reduce its effective tax rate from 24.4% last year to this number last quarter.

$2 billion. This is how much more the company thinks it could report in sales in 2016 than it previously thought. Following a better-than-expected Q1 and in the wake of improving currency exchange rates, Pfizer upped its full-year revenue outlook to between $51 billion and $53 billion. Previously, management was projecting sales of between $49 billion and $51 billion.

14.2. That's Pfizer's current P/E ratio following management's decision to bump up its adjusted EPS outlook for this year. The company expects to deliver at least $2.38 in EPS in 2016, up nicely from previous expectations of $2.20. 

Tying it together
It's been years since Pfizer could be considered by investors to be a growth stock, but now that the negative impact of losing patent protection on its megablockbuster drug Lipitor in 2011 is behind it, Pfizer seems to be back on track. Given Pfizer's improving outlook and the fact that it has envy-inspiring financial firepower that it can use to strengthen its product pipeline and reward investors, I think Pfizer is worthy of consideration as a core holding in any healthcare portfolio.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.